Solution Manual for: Numerical Computing with MATLAB

  

Solution Manual for: Numerical Computing with MATLAB

by Cleve B. Moler

John L. Weatherwax?

July 25, 2007

Chapter 7 (Ordinary Differential Equations) Problem 7.1

The algorithm BS23 can be represented by the following sequence of steps

s1 = f (t,,,, y,,,) (5)

h h

s2 = f(t,,, + 2 , y,,, + 2 s1) (6)

3 3

s3 = f(t,,, + 4h, y,,, + 4s2) (7)

y,,,+1 = y,,, + h 9(2s1 + 3s2 + 4s3) (8)

Part (a): The specific ODE’s (and their exact solutions) to consider are given by

dy

dt dy

dt dy

dt dy

dt

For the first system, dy/dt = 1, so f (t, y) = 1 then the BS23 procedure gives the following

s1 = 1 (13)

s2 = 1 (14)

s3 = 1 (15)

y,,,+1 = y,,, + 9h(2+3+ 4) = y,,,+ h (16)

Does this equal the true solution at t,,, + h? We evaluate the above to obtain

                  y(t,,, + h) = (t,,, + h) + C = t,,, + C + h = y,,, + h (17)

and the answer is yes. For the second function f (t, y) = t we see that the BS23 procedure is

s1 = t,,, (18)

h

s2 = t,,, + (19)

2

3

s3 = t,,, + 4h (20)

y,,,+1 = y,,, +

h h 3

2 (2t,,, + 3(t,,, + 2 ) + 4(t,,, + 4h)) (21)

Simplifying this last equation we have

h

= yn + 9 (9tn + (32 + 3)h) (22)

h

= yn + htn + 9 (92)h (23)

h2

= yn + htn + (24)

2

Again we ask, does this equal the true solution at tn+1? Lets check by evaluating

y(tn+1) = y(tn + h) = 2(tn + h)2 + C = t2

1 2 + C + htn + h2

n 2 = y(tn) + htn + h22 (25)

and we see that the answer is yes. For the second function f (t, y) = t2, then the BS23 gives

s1 = t2 (26)

n

h

s2 = (tn + 2 )2 (27)

3

s3 = (tn + 4h)2 (28)

yn+1 = yn + h 9 (2t2 n + 3(tn + h2 )2 + 4(tn + 34h)2) (29)

Now simplifying the last equation we have

yn+1 = yn + h9(2t2 n + (3 + 6)htn + (34 + 94)h2) (30)

h

= yn + 9 (9t2 n + 92htn + 124 h2) (31)

= yn + ht2n + h2tn + h3 1 (32)

3

Does this equal the exact solution at tn + h? To decide we compute

y(tn + h) = (tn + h)3

3 + C == 31(t3n + 3t2nh + 3tnh2 + h3) + C (33)

t3

= 3 + C + (t2

                                       n nh + tnh2 + h33 ) (34)

and we see that the answer is yes. Finally, for the function f (t, y) = t3, the BS23 algorithm gives

s1 = t3 (35)

n

h 3 3 1

s2 = (tn + 2 )3 = t3 n + 2t2 nh + 4tnh2 + 8h3 (36)

3

s3 = (tn + 4h)3 = t3 n + 94 t2 nh + 27

16tnh2 + 27

64h3 (37)

yn+1 = yn + 9 h (2t3 n + 3(t3 n + 3 2t2 nh + 3 4tnh2 + 81 h3) (38)

9 27 27

+4(t3 n + 4t2 nh + 16tnh2 + 64h3)) (39)

Simplifying this last term gives

yn+1 = yn + ht3 n + 3 2t2 nh2 + tnh3 + h4 (40)

6

The true solution at tn + h however is equal to

y(tn + h) = (tn + h)4

4 + C = 41 (t4n + 4t3 nh + 6t2nh2 + 4tnh3 + h4) + C (41)

1

= 4t4n + C + tn3h + 32t2 nh2 + tnh3 + h4 (42)

4

3 h4

= yn + ht3 n + 2t2 nh2 + tnh3 +  4 . (43)

Since this differs from the the approximate solution by (16 ? 1 ~ h4 we see that this method

4

is not exact for f (t) = t3.

Part (b): The BS23 error estimate is given by

en+1 = 72h (?5s1 + 6s2 + 8s3 ? 9s4) (44)

where si for i = 1, 2, 3, 4 is computed as above. When one computes s1, s2, s3, and s4 for f (t) = 1 and f (t) = t one obtains a zero estimation error. Considering the function f (t) = t2 we have an estimated error given by

en+1 = 72h (?5t2n + 6(tn + 2h)2 + 8(tn + 34h)2 ? 9(tn + h)2) (45)

when one expands the above expression one obtains

en+1 = ?

h3

(46)

24

which is not zero. Thus the estimated error is exact for f (t) = 1 and f (t) = t only.

Problem 7.4

See the matlab code in the file prob 7 4.m.

Problem 7.5

Part (a): See the matlab code in the file myrk4.m.

Part (b): The local truncation error of RK4 is given by O(h4+1), so the global truncation error should be O(h4). When you decrease the step size h by 2 this should reduce the global error by 1/24 = 1/16. An experiment illustrating this behaviour can be found in

the routine/code prob 7 5.m. There we sequentially decrease the stepsize parameter h and compute the global error between the final timestep and the known true solution value. We then plot the log of stepsize parameter v.s. the log of the global error. On this plot one can see that in this space we have a linear decrease in error representing a powerlaw. A linear function is fitted to to this data with the Matlab function polyfit. The slope of this line is given by 4 empirically displaying the known relation between the error and the stepsize of

error ? h4

Part (c): For this problem formulation our differential equation is given by y¨ = ?y. The system formulation for this equation is given by defining

[y1(t) J [ y(t) J

Y = = (47)

y2(t) ?y(t)

then

J J J

d [ y(t)

d [ ?y(t) [ y2(t)

Y (t) = = = (48)

                   dt dt ?y(t) ¨y(t) ?y1(t)

so in total in terms of y1 and y2 the differential equation is

[ y1 J [ y2 J

= (49)

y2 ?y1

This is implemented in the Matlab code prob 7 5 fn.m. In addition, in the driver routine prob 7 5.m we have implemented the numerical experiments mentioned in the book and have verified the statements there.

Problem 7.6

Part (a): The differential equation

y? = ?1000y + 1000 sin(t) + cos(t) with y (0) = 1 (50)

has a homogeneous solution given by y(t) = Ce?1000t and a particular solution given by a function of the form A sin(t) +B cos(t). By putting this particular solution into the equation above we can solve for the coefficients A and B. When we do this we get the following

A cos(t) ? B sin(t) = ?1000A sin(t) ? 1000B cos(t) + 1000 sin(t) + cos(t) (51)

Grouping the coefficients of cos(t) and sin(t) we obtain

(A + 1000B ? 1) cos(t) + (?B + 1000A ? 1000) sin(t) = 0. (52)

When we require that the coefficients of cos(t) and sin(t) vanish we obtain the following system of equations

A + 1000B ? 1 = 0 (53)

?B + 1000A ? 1000 = 0. (54)

The solution to the first equation in terms of B is given by A = 1?1000B. When substituted into the second equation we obtain

1000(1 ? 1000B) ? B = 1000 (55)

Which has as its solution B = 0. Thus A = 1 giving in total the solution y of

y(t) = sin(t) + Ce?1000t (56)

using the initial condition y(0) = 1 we obtain C = 1 and the total analytical solution is given by

y(t) = e?1000t + sin(t) (57)

I should mention that heuristically this problem is midly stiff because of the various time scales present in the solution. The exponential term has a timescale O (1/1000) while the sin term has a timescale like O (1) or effectivly three orders of magnitude different.

Part (b)-(f): See the routines prob 7 6.m and prob 7 6 fn.m for an implementation of this problem.

Problem 7.7

Part (a): Each equation has as its solution y(t) = sin(t).

Part (b): The corresponding first order system for the third given differential equations is (defining y1(t) = y(t))

 y1   y2   0 1   y1 

= = (58)

y2 ?y1 ?1 0 y2

The corresponding system for the fourth differential equation is given by

d  y1  y2  0 1

  y1

0

= = + (59)

dt y2 ? sin(t) 0 0 y2 ? sin(t)

Note that the first representation above is autonomous while the second is not.

Part (c): The Jacobian for each of the functions f involved in the definitions of each

differential equation are given by

?f1 ?y

= 0

?f2 ?y

y

=

1 ? y2

?f3 ?y

?f4 ?y

 0 1 

?1 0

 0 1

00

From the above we can see that as t ? ?2 that WWX finish

Problem 7.9

Consider the matrix A given by

?

?? 0 ?

A = ?0 ?? ? ?? ? ?1

?

? (60)

Expanding the determinant of the above matrix we have

|A| = ??| ?? ?

? ?1 | ? ? | 0 ?

?? ? | (61)

or

|A| = ??(? ? ??) ? ?(??) (62)

or

                              |A| = ?2 ? ?? + ? (63)

Setting this equal to zero to find the values where the matrix is singular we see that

? = ± ?(? ? 1) . (64)

Which was the expression we were looking to find. To find the vectors in the nullity of A when ? is one of these special values, insert this into the matrix above and reduce it to row-echelon form. Inserting this expression into A means we are looking for a vector v such that

dividing the first row in the above expression by ? and the second row by ?? we obtain

Now multiplying the first row by ± ?(? ? 1) and adding it to the third row we obtain

which simplifies to

(??1) 

1 0 ? ?

0 1 ?1

0 ? ??

which demonstrates that the third row is indeed a multiple of the second row. Eliminating this row we obtain the following requirements among the coefficients of v

v1 = ±

(? ? 1)

?

v3 (69)

v2 = v3 (70)

~Letting v3 = ? = ?(? ? 1) and assuming that ? ? 1 > 0 we see that the above null vector has components given by

v1 = ? ? 1 (71)

v2 = ? (72)

v3 = ? (73)

as desired.

Problem 7.10 (the Jacobian of the Lorenz equations)

The Lorenz equations are given by y? = Ay, with

? ? ? ?

y1(t) ??0 y2(t)

y(t) = ? y2(t) ? and A = ? 0 ?? ? ?

y3(t)?y2(t)? ?1

?y1 = ??y1(t) + y2(t)y3(t)

?y2 = ?? y2(t) + ? y3(t)

?y3 = ?y1(t)y2(t) + ?y2(t) ? y3(t) .

This expression makes it easier to compute the required Jacobian of our mapping f (·). We find that

The fixed points of the Lorentz equations are given by solving for y in f (y) = 0, which gives the following system of equations

??y1 + y2y3 = 0

?? y2 + ? y3 = 0

?y1y2 + ?y2 ? y3 = 0.

The second equation above has the simple solution of y2 = y3, which when used in the first and third equaions above gives

Performing the matrix multiplication we have for the full non-linear system representing the

Lorenz equations, the following

??y1 + y22 = 0

?y1y2 + ?y2 ? y1 = 0 .

The last equation above can be factored as y2(?y1 + ? ? 1) = 0, which has as solutions y2 = 0, and y1 = ? ? 1. Following the consequences of each of these choices, if y2 = 0, then y1 = 0, while if y1 = ? ? 1 then the first equation above gives

??(??1) +y22 =0,

which has a solution given by

~

y2 = ± ?(? ? 1) .

Thus in summary then the three fixed points of the Jacobian of the Lorentz equations are

(y1, y2, y3) (y1, y2, y3)

=

=

(0, 0, 0)

(? ? 1, ?(? ? 1), ?(? ? 1))

~ v

(y1, y2, y3)

=

(0, 0, 0).

Peoplesoft Upgrade Manual

Thanks to the wide availability of the Internet all over the world, it is now possible to instantly share any file with people from all corners of the globe. On the one hand, it is a positive development, but on the other hand, this ease of sharing makes it tempting to create simple websites with badly organized databases which make users confused or even frustrated.

We want you to feel “at home” here, so we took our time to make this website as user-friendly as possible. Whether you are looking for a handbook or a rare ebook, the chances are that they are available for downloading from our website in txt, DjVu, ePub, PDF formats. You no longer need to visit the local libraries or browse endless online catalogs to find Peoplesoft Upgrade

Manual. Here you can easily download Peoplesoft Upgrade Manual pdf with no waiting time and no broken links. If you do stumble upon a link that isn’t functioning, do tell us about that and we will try to answer you as fast as possible and provide a working link to the file you need.

Is there any particular reason why you should use our website to download Peoplesoft Upgrade Manual pdf file? For starters, if you are reading this, you have most likely found what you need here, so why go on to browse other websites? Even if your search has been fruitless yet, we have an impressive database of various ebooks, handbooks, and manuals, so if you are looking for a rare title, your chances of finding it here are quite high. In addition, we do our best to optimize your user experience and help you download necessary files quickly and efficiently. We make sure that all our files are available in PDF format, which is currently one of the most popular document formats for computers and mobile devices. Finally, we are always ready to help you if you are having trouble using the website or are unable to find a particular title.

service manual for toshiba sr 305, 2017 design and build contract guide, acs organic chemistry study guide 2013, timeslips 2016 user manual, 1970 100 hp mercury motor manual, hiding place study guide answers, biology experience laboratory manual edition 7 answers, mercedes benz c220 cdi manual spanish, melroe clark 500 manual, cebora dallas 80 manual, autodesk inventor fusion manual, sears craftsman lt 4000 owners manual, strength and conditioning manual florida, kinns computer concepts study guide answer key, repair manual bmw e46 318i, fini tiger compressor mk 2 manual, spanish interpreter study guide, 30 hp yamaha outboard owners manual, mercedes benz w164 repair manual, palatek 15d manual, british gas up2 user guide, manual drexel slt30, mtd 830 repair manual, haynes ford focus manual, 2001 ford f150 manual transmission fluid, study guide arthropods answers, hyundai accent usa user manual, jehovahs witness weekly study guide, owner manual 2018 ford, gts 4 r33 workshop manual, generac g23 manual, middle school praxis study guide, wacker parts manual 4045, scanlab rtc3 installation manual, renault espace electric manual, 2010 toyota highlander service manual, fanuc macro programming manual lathe, iveco daily manual torrent, 2017 mercury outboard 225hp optimax repair manual, radiology cpt code easy guide 2016, haynes automotive electrical and electronics systems manual, dufour sailboat owners manual, audi allroad manual, ktm 125 gs manual, 1986 ezgo service manual, erlanger medical ethics orientation manual, bmw 318i n42 repair manual, preppers guide, cch australian master tax guide 2013, mcgraw hill data management solutions manual odd, medical practice manager study guide, 2015 flht electra glide owners manual, yamaha ybr 125 2016 manual, manual for snorkel sl20 lift parts, 2018 yamaha grizzly 450 service manuals, 2004 suzuki intruder 1500 service manual, 1996 ford aerostar service manual, kuhn fc 300 rg manual, 39 guide ap biology, guide reader quiz, environmental science multiple choice study guide answers, daihatsu dm950d engine manual, ams investigations manual answers, 2004 toyota hilux 2wd workshop manual, student solution manual fundamentals physics 7th edition, guide whittle, instructor manual lab ccna 2, red lobster operations and training manual, review guide biology, removing 98 s10 manual transmission

peoplesoft financials web-based training peoplesoft 9.1 upgrade - toolbox

for it groups peoplesoft upgrade: is the time right? - peoplesoft upgrade - peoplesoft pages peoplesoft tutorial - become awesome in peoplesoft update manager ( peoplesoft technology peoplesoft hcm 9.2 strengthens healthcare user's keys to making nationwide's peoplesoft 9.2 upgrade a quick peek at the peoplesoft upgrade resources peoplesoft documentation | it@umn peoplesoft upgrade manual pdf peoplesoft | applications | training | oracle 9.2 upgrade planning - toolbox.com upgrading peoplesoft, part 2: installation and peoplesoft human capital management 9.0 to 9.2 peoplesoft 9.2 upgrade planning guide peoplesoft 9.2 upgrade | symphony corporation 5 steps to understanding the peoplesoft update the planning guide to peoplesoft 9.2 upgrade - upgrading peoplesoft, part 1: the first steps - peoplesoft upgrade guide peoplesoft upgrade manual pdf ataway lessons learned: upgrading to peoplesoft peoplesoft upgrade - toolbox for it groups peoplesoft hr 9.2 upgrade faqs v5 - arizona state care first: peoplesoft hcm 9.1 upgrade | peoplesoft peopletools data management and best practices in upgrading your peoplesoft financial information systems - peoplesoft | peoplesoft financials 9.2 upgrade - georgiafirst peoplesoft 9.1 upgrade best practices - upload, peoplesoft upgrade overview peoplesoft upgrade manual pdf peoplesoft upgrade methodology | oracle community peoplesoft 9.1 upgrade : university of vermont

Related bug:

Service Manual For Toshiba Sr 305, 2017 Design And Build Contract Guide, Acs Organic Chemistry Study Guide 2013, Timeslips 2016 User Manual, 1970 100 Hp  Mercury Motor Manual, Hiding Place Study Guide Answers, Biology Experience  Laboratory Manual Edition 7 Answers, Mercedes Benz C220 Cdi Manual Spanish, Melroe Clark 500 Manual, Cebora Dallas 80 Manual, Autodesk Inventor Fusion  Manual, Sears Craftsman Lt 4000 Owners Manual, Strength And Conditioning  Manual Florida, Kinns Computer Concepts Study Guide Answer Key, Repair  Manual Bmw E46 318i, Fini Tiger Compressor Mk 2 Manual, Spanish Interpreter  Study Guide, 30 Hp Yamaha Outboard Owners Manual, Mercedes Benz W164 Repair  Manual, Palatek 15d Manual, British Gas Up2 User Guide, Manual Drexel Slt30, Mtd 830 Repair Manual, Haynes Ford Focus Manual, 2001 Ford F150 Manual  Transmission Fluid, Study Guide Arthropods Answers, Hyundai Accent Usa User  Manual, Jehovahs Witness Weekly Study Guide, Owner Manual 2018 Ford, Gts 4  R33 Workshop Manual, Generac G23 Manual, Middle School Praxis Study Guide, Wacker Parts Manual 4045, Scanlab Rtc3 Installation Manual, Renault Espace  Electric Manual, 2010 Toyota Highlander Service Manual, Fanuc Macro  Programming Manual Lathe, Iveco Daily Manual Torrent, 2017 Mercury Outboard 225hp Optimax Repair Manual, Radiology Cpt Code Easy Guide 2016, Haynes  Automotive Electrical And Electronics Systems Manual, Dufour Sailboat Owners Manual, Audi Allroad Manual, Ktm 125 Gs Manual, 1986 Ezgo Service Manual, Erlanger Medical Ethics Orientation Manual, Bmw 318i N42 Repair Manual, Preppers Guide, Cch Australian Master Tax Guide 2013, Mcgraw Hill Data  Management Solutions Manual Odd, Medical Practice Manager Study Guide, 2015  Flht Electra Glide Owners Manual, Yamaha Ybr 125 2016 Manual, Manual For  Snorkel Sl20 Lift Parts, 2018 Yamaha Grizzly 450 Service Manuals, 2004  Suzuki Intruder 1500 Service Manual, 1996 Ford Aerostar Service Manual, Kuhn Fc 300 Rg Manual, 39 Guide Ap Biology, Guide Reader Quiz, Environmental  Science Multiple Choice Study Guide Answers, Daihatsu Dm950d Engine Manual, Ams Investigations Manual Answers, 2004 Toyota Hilux 2wd Workshop Manual, Student Solution Manual Fundamentals Physics 7th Edition, Guide Whittle,

Instructor Manual Lab Ccna 2, Red Lobster Operations And Training Manual, Review Guide Biology, Removing 98 S10 Manual Transmission 

CDP-TX-01 & CDP-RX-01S

UHF FM-NARROW BAND RADIO DATA MODULE

Operation Guide

Version 1.6 (August 2000)

CIRCUIT DESIGN, INC.,

International Business Division

7557-1 Hotaka, Hotaka-machi, Minamiazumi, Nagano 399-8303. JAPAN

Tel: + +(0263)-82-1010 Fax: + +(0263)-82-1016

CIRCUIT DESIGN, INC.

CONTENTS

GENERAL DESCRIPTION & FEATURES

3

CDP-TX-01 transmitter module 

4

CDP-RX-01 receiver module

5

OPERATION INSTRUCTIONS.

6

Supply voltage 

6

Data input

6

Data

7

Satrt up

7

Outputs

8

Test Set ECB-01 and DCB-01 

8

Antennas 

8

SPECIFICATIONS

10

BLOCK DIAGRAM

11

DIMENSIONS

12

TEST DATA OF CDP-TX-01

13

TEST DATA OF CDP-RX-01

14

CDP-01 UHF Synthesized Radio Data Module Operation Guide 2

CIRCUIT DESIGN, INC.

GENERAL DESCRIPTION & FEATURES

Features

* 434 MHz UHF band, compatible with European I-ETS 300-220 standard

* Very small compact integrated device with robust metal housing

* New integrated UHF filter technology

* FM narrow band modulation and high frequency stability

* Low current consumption, ideal for mobile application

* Registration and charge exempt in Germany, Switzerland, Sweden, Norway, Denmark,The Netherlands and Austria.

Applications

* Radio remote control cranes & machines

* Radio remote control for garage door controls

* Security systems

* Room surveillance

* Theft protection

* Telemetry systems for model aircraft

General description

The crystal-controlled single-frequency radio data module CDP-TX-01 (transmitter) and CDP-RX-01 (receiver) is suitable for various application fields such as wireless data communication, remote control, telemetry or wireless security systems. It is easy to use and integrate into application systems.

The small size and low power consumption of the CDP-01 make it ideal for mobile applications where its interference rejection and practical distance range is far better than similar RF modules based on wide band SAW-resonator frequency generators.

Standard RS232 serial data and other digital data (TTL level), such as pulse width modulation signals and signals from standard encoder-decoder circuits of the given AF bandwidth, can be transmitted.

Radio licences

The CDP-01 has received radio licence from the following countries. You can use and integrate the CDP-01 in your application and operate it without further registration and free of charges in these countries.

Country

Technical guideline

Approval number

Frequency

Germany

17TR 2100

G750 467D

434 MHz

Switzerland

SR 784.103.12/1.19

BAKOM 94.0417.K.P

434 MHz

Sweden

TFS B:92D

Ue 950007

434 MHz

The Netherlands

I-ETS 300 220

NL95072574

434 MHz

Austria

FTV505

CEPT LPD A 70004

434 MHz

Norway

I-ETS 300 220

NO 96000103R & 104R

434 MHz

Denmark

TB94 060

ALR9636

434MHz

CDP-01 UHF Synthesized Radio Data Module Operation Guide 3

CIRCUIT DESIGN, INC.

EMC

The CDP-01 was tested at the competent body in Germany and proved to be comply with prl-ETS RES 0908 (June 1995). EMC Type-Examination Certificate for CDP-01 was issued by German BET. The CE mark is printed on the CDP-01 being shipped from the factory at CIRCUIT DESIGN after January 1, 1996.

CDP-TX-01 transmitter module

The CDP-TX-01 is an UHF FM-narrow band transmitter with crystal oscillator for high frequency stability. Modern SMT technology and the application of a unique integrated SAW (Surface Acoustic Wave) filter element for the elimination of harmonics and spurious emissions enable a small size - much smaller than a match box.

The narrow band FM modulation (direct FSK) allows efficient use of the available RF spectrum. Different modules can operate in a 12.5 KHz channel spacing scheme unlike SAW resonator transmitters which use a very broad band of the frequency spectrum.

The CDP-TX-01 can transmit any 5 Volt digital input data in the specified frequency range. Analog data is digitized by the internal comparator.

The transmission is physically done by a flexible Lambda/4 antenna fixed to the transmitter module. The amount of radiated power and directional behaviour is influenced by the surrounding of the transmitter module. Installation in a bigger metal housing with ground connected to the transmitter module housing and transmitter antenna put into an upright position outside the metal housing will reduce the antenna impedance and increase the radiated power. For best performance in a user system general rules of radio frequency technology should be taken into consideration.

The same should be applied to the receiver.

CDP-01 UHF Synthesized Radio Data Module Operation Guide 4

CIRCUIT DESIGN, INC.

CDP-RX-01 receiver module

The CDP-RX-01S is an UHF receiver for FM-narrow band modulated signals. The receiver design is based on the double Super-heterodyne principle with crystal control enabling high signal sensitivity, high selectivity, and high frequency stability not achieved by simple SAW resonator receivers or other low cost designs.

Extensive filtering by an integrated unique SAW filter element enables operation in hazardous areas where interference may be expected. Steadily increasing use of the available frequency spectrum demands the application of narrow band systems for maximum operation reliability and fairness to other users of the ISM band.

The CDP-RX-01S receiver module is designed to match the CDP-TX-01 transmitter module, though signals from other FM-narrow transmitters can be received as well.

The receiver frequency must match with the transmitter frequency to enable reception. The CDP-RX-01S is designed for PCB mounting. A simple wire can be soldered to the antenna input or the antenna can be printed on the PC board. Better performance is attained with commercial antennas for the 434MHz ISM band.

The receiver modules have two different outputs and an RSSI field power output which indicates the power of the incoming RF signal.

The AF output is the analog output from the FM detector circuit. Voltage level, DC-offset and AF noise depend directly on the receiver input signal. This output can be connected to an MSK decoder circuit if a transmitter with additional MSK encoder is used. For simple FSK modulation of digital data the DATA OUT terminal can be used. It contains a bandpass filter and comparator with digital output (open collector). With additional filtering, the sensitivity of the receiver is increased and the digital output signal can easily be connected to other digital circuits.

To achieve the high signal sensitivity and short receiver response time no internal muting is applied. Valid data signals can be detected by utilising the RSSI output.

CDP-01 UHF Synthesized Radio Data Module Operation Guide 5

CIRCUIT DESIGN, INC.

OPERATION INSTRUCTIONS

Please read these instructions before you start using the CDP-01.

The CDP-01 is designed as a module which will be integrated into a user system. It is not a ready-made product for private users. It can be regarded more like a special component for part of an electronic system. The user needs basic knowledge about electronics. Special knowledge about RF technology is helpful, but the most difficult parts are integrated into the modules to enable easy operation. Some additional information is given here:

Supply voltage:

The transmitter and receiver module contain a voltage regulator to guarantee stable performance in the given range of supply voltage.

The design was made for operation with a 6 or 9 Volt battery. If the battery voltage drops under the minimum voltage given in the technical specifications, the transmitter output power will drop and the RF oscillator will stop operation. No data can be transmitted in this case. The receiver will continue to work down to a certain voltage but the performance will deteriorate.

If the voltage connected to the Vcc (+) and Ground (-) terminal is beyond the maximum voltage given in the technical specification the internal voltage regulator will be permanently damaged. The result is an internal short-circuit or disconnection.

To enable a low minimum voltage no internal circuit is used to prevent damage by incorrect

polarity. If the transmitter is connected incorrectly, it will be permanently damaged.

If a higher supply voltage is available then a simple diode can be inserted in connection line to the Vcc terminal to prevent damage by incorrect polarity. The diode must be rated for the maximum supply current detailed in the technical specifications.

Modules which have been connected to improper voltage sources should be sent back to the dealer for inspection.

Data input:

The data input at the transmitter is connected by a feed-through/capacitor to minimise RF emission from or through this terminal. The data source must be able to drive a capacitive load of 1nF. The data input terminal is connected via a 10KOhm resistor to a digital CMOS compatible input. (See Block Diagram.) Data sources of high impedance can be used if the capacitive load of the data input is acceptable.

The voltage of the data signal should be between 0V (Ground level) and Vcc. Because of the internal voltage regulator, it is recommended that the data high level be limited to 5 Volts.

The data can be an analog or digital signal. Analog signals will be converted to a digital 1 or 0 inside the transmitter.

It is not necessary to synchronize the data signal of the transmitter, but the data signal should be fed to the transmitter 20ms after the transmitter power on.

CDP-01 UHF Synthesized Radio Data Module Operation Guide 6

CIRCUIT DESIGN, INC.

Data format:

The digital data fed to the transmitter is passed through an internal low-pass filter to limit the bandwidth of the digital data. This is needed for an efficient use of the available RF spectrum. At the receiver, a band-pass filter is used to recover the data signal from noise. Together the transmittable signal bandwidth is approximately 100 Hz to 2400 Hz. At the receiver, the signal is converted back into a digital signal for compatibility with succeeding digital systems. The type of digital data signals transmittable is limited because of the bandwidth of the system.

Long intervals of HIGH or LOW bits should be avoided. Succeeding bits can be distorted in their bit length. If the sequence of HIGH or LOW bits is too long it is possible that the logic level of the data output will change.

The best countermeasure is to use a digital encoding scheme which guarantees that no low frequency components are included in the data signal. This can be achieved for example with the “Manchester” encoding. A digital 1 is coded in a sequence of 10 and a digital 0 is encoded into a sequence of 01. In most cases it is also sufficient to transmit serial data by using start and stop bits of different logical level as it can be done according to the RS232 format. Each transmitted byte will be preceded by a 0 bit and succeeded by a 1 bit.

It will be very helpful to have a conduct pulse in front of the data. A conduct pulse of 1200bps, 50% duty cycle in 20ms is recommended.

At higher data rates (4800 Baud) the internal signal is shaped into a slope and bit-length distortion at the receiver data output increases.

The CDP-01 was tested with a number of standard encoder-decoder IC's for simple remote controls. For data speeds in the 300 to 4800 Baud range no trouble should occur.

Because of the wide variety of data formats, data speeds and digital modulations techniques, it is best to set-up a ‘worst case’ situation and test the data transmission before the CDP-01 is used in a practical application.

Further advice can be given if the precise format of the data and system requirement is notified to the dealer or directly to Circuit Design, Inc. Your inquiries and comments are welcome and will also help other users.

Start-up:

After Vcc is connected to the transmitter the RF oscillator will start-up and, after about 10ms, the output frequency and power will reach the normal value. The same start-up time is needed by the receiver after it is switched on. In addition differences in the transmitter and receiver oscillator frequency can produce a DC shift in the receiver output voltage that requires a certain amount of time to be compensated for by the internal circuit.

Data transmission is not possible, or the data will be distorted, during this start-up time.

Therefore the input signal should be fed to the transmitter 20ms after TX power ON.

The transmitter is active as long as the power supply is on. The power should be switched off immediately after the data transmission is finished in order to save valuable battery power and avoid unnecessary use of the RF spectrum.

The receiver does not use the RF spectrum actively and it can remain ON as long as desired.

CDP-01 UHF Synthesized Radio Data Module Operation Guide 7

CIRCUIT DESIGN, INC.

Outputs:

At the receiver side 3 output signals are available.

AF is the direct analog output of the FM receiver.

This signal can be used for checking the receiver and in cases where signals with additional analog modulation are to be received. For example, it can be connected to an MSK decoder.

The DATA output is a digital open collector output. An internal 22KOhm pull-up resistor is applied to enable direct connection to CMOS compatible circuits. For other applications an additional external pull-up resistor should be used.

The receiver has no internal mute circuit to avoid delays and achieve maximum sensitivity.

The AF and DATA output will show noise on the output when no signal is received.

The third output is called RSSI. It is an indicator of the received signal strength. It can be used to drive an external mute circuit.

Test Set ECB-01 and DCB-01:

The Test Set (ECB-01 and DCB-01) was developed to demonstrate and test the CDP-01 RF data module. In combination with the CDP-TX-01 and CDP-RX-01S modules, it is a full four command radio remote control that can be used for various practical applications.

The CDP-01 Test Set will save time and effort in deciding new developments that incorporate the CDP-01 radio modules as the radio link.

Antennas:

Most important for safe data transmission is a good antenna, and RF grounding, both for the transmitter and the receiver. Without an antenna it is impossible to transmit data over a long distance range.

It is a Lambda/4 wire protected by a plastic cover. The transmitter antenna may not be extended or cut or replaced by another antenna or connector. This would cancel the radio licence and operating unlicenced radio equipment is illegal.

The receiver has a simple antenna input pin. Any suitable UHF antenna can be connected to it. The easiest way to connect an antenna to the CDP-RX-01S is to solder a 17cm wire directly to the antenna input. If the receiving antenna is installed away from the receiver module, a 50 Ohm Coax antenna wire can be used. The shielding of the antenna wire should be soldered to the case near the antenna input of the CDP-RX-01S.

It is possible, but not recommended, to connect the receiver module and the antenna by a connection on a PCB. This will decrease the receiver performance in most cases.

To find the best method of installation for the transmitter and receiver, many things should be considered and tested. It is recommended that the user read specialized literature on antennas and radiation characteristics to gain a better understanding of these fields. A detailed explanation cannot be given here.

In most cases the following basic rules will help you.

CDP-01 UHF Synthesized Radio Data Module Operation Guide 8

CIRCUIT DESIGN, INC.

* Connect an antenna with 50 Ohm impedance for 434 MHz.

The easiest construction is a wire of approximately 17cm.

* Place the antenna vertically, straight up or down from the transmitter and receiver module.

* Do not cover the antenna with metal parts.

* The connection of the metal surface of the transmitter and receiver case to a larger metal part (ground plane) will increase radiation and reception efficiency. Such metal part should not be placed near the antenna.

* Best range is achieved if the transmitter and receiver antenna have a direct visual connection. Any object in between the transmitter and receiver antenna, and metallic objects in particular, will decrease the range.

* The transmission is influenced by reflections of the transmitter signal on metallic surfaces. By overlaying the direct and reflected signal with a 180 degree phase shift the signal can nearly fade out. Such reflections and fade-outs can result in data drop-outs in mobile applications.

* The human body can have similar effects like metal objects. Pocket transmitters should be taken in the hand and put in a position away from the body and pointed in the direction of the receiver.

CDP-01 UHF Synthesized Radio Data Module Operation Guide 9

CIRCUIT DESIGN, INC.

SPECIFICATIONS

COMMON:

COMMUNICATION FORM One way

OSCILLATION SYSTEM Crystal

FREQUENCY I-ETS 300 220 EURO TYPE 433.920 MHz 434.075 MHz

NUMBER OF RF CHANNELS Single (fixed)

FREQUENCY STABILITY ±2.5 KHz (-10 to +55°C)

FREQUENCY RESPONSE 100 Hz to 2.4 KHz

BAUD RATE 300 to 4,800 bps

OPERATING TEMPERATURE RANGE -10 to +60°C

TYPE APPROVAL Germany, Switzerland, Sweden, The Netherlands,

Austria, Norway, Denmark, EMC

TRANSMITTER:

TRANSMITTER TYPE Fixed channel

RF OUTPUT POWER 10 mW +0 / ±3 dB at 50 Ohm

TRANSMITTER START UP TIME 10mS

MODULATION FM narrow

DATA INPUT LEVEL 5 V

INPUT SIGNAL Digital

DEVIATION 2.5 KHz

SPURIOUS EMISSION <-60 dBm

ADJACENT CHANNEL POWER <200 nW

SUPPLY VOLTAGE 5.5 to 10 V

SUPPLY CURRENT 18 mA (TYP)

DIMENSIONS 36 ? 26 ? 10 mm

WEIGHT 9.8 g

RECEIVER:

RECEIVER TYPE Double superheterodye fixed channel

SENSITIVITY -120 dBm (12 dB / SINAD, CCITT filter)

SELECTIVITY ±5 KHz at -6 dB point

DEMODULATION FM narrow

DISTORTION <5 % at 1 KHz

S/N RATIO 50 dB overall (AF OUT)

DATA OUTPUT LEVEL Open collector (digital)

OTHER OUTPUT RSSI and AF

SUPPLY VOLTAGE 4.5 to 14 V

SUPPLY CURRENT 10 mA (TYP)

DIMENSIONS 50 ? 30 ? 7.5 mm

WEIGHT 19 g

CDP-01 UHF Synthesized Radio Data Module Operation Guide 10

CIRCUIT DESIGN, INC.

BLOCK DIAGRAM

CDP-TX-01

ANT

DC INPUT

CDP-RX-01

ANT

3

CDP-01 UHF Synthesized Radio Data Module Operation Guide 11

CIRCUIT DESIGN, INC.

DIMENSIONS

CDP-TX-01

CDP-RX-01S

CDP-01 UHF Synthesized Radio Data Module Operation Guide 12

CIRCUIT DESIGN, INC.

TEST DATA OF CDP-TX-01

MKR:434MHz 10.93dBm AT 25dB# RB 30kHz# A:POS

RLV: 15.0dBm ST 6.7s VB 30kHz

START:0Hz [BAND 0] STOP:2.000GHz

SPURIOUS EMISSION

MKR:434.075 02MHz 11.09dBm AT 30dB RB 100Hz A:POS

MKR:434.075 00MHz - 1.44dBm AT 30dB RB 1kHz A:POS

RLV: 10.8dBm ST 150ms VB 1kHz

CENTER:434.075 00MHz [BAND 0] SPAN:50.0kHz

RF-MODULATION

CENTER:434.075 00Hz [BAND 0] SPAN:10.0kHz 100Hz 1KHz 10KHz

RF BANDWIDTH AF BANDWIDTH

CDP-01 UHF Synthesized Radio Data Module Operation Guide 13

CIRCUIT DESIGN, INC.

TEST DATA OF CDP-RX-01

RX:SIGNAL/NOISE RATIO (dB/dB?)

RX:RSSI-OUTPUT (V/dB?)

AF BANDWIDTH

1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 5V

RX: CURRENT/VOLTAGE (mA/V)

CDP-01 UHF Synthesized Radio Data Module Operation Guide 14

Session 2563

Experiences in Continuous Improvement of “Computer-Aided Manufacturing Systems”

Richard Jerz

St. Ambrose University

Abstract

       The development and continuous improvement efforts for the industrial engineering course “Computer Aided Manufacturing Systems” at St. Ambrose University are described in this paper. This course has undergone major changes to stay current with computer-aided manufacturing technology and to meet ABET accreditation guidelines for design and integration. Open-ended laboratory assignments were introduced to stimulate thinking and to add design content. Integration with other engineering courses was carefully considered. Improvements in the classroom lectures and laboratory assignments were made.

       St. Ambrose University’s industrial engineering program is small and operates on a limited budget. The small budget presented a particularly difficult challenge in determining which equipment and software to use or purchase. Course development has been financed through creative use of existing laboratory equipment, internal department funding, faculty redevelopment initiatives, educational discounts for software products, in-kind gifts, and low cost upgrades of existing laboratory computers. It was discovered that course objectives could be met without having to spend much money, but that improvements had to be phased in over the years. An overview of the course objectives, laboratory equipment and assignments, funding methods, professor and student’s observations, and plans for future improvements are provided.

Introduction

       The use of computer-aided technologies by industry has grown enormously in recent years. Practically all modern manufacturing organizations use computers in one form or another: to design and test product ideas (CAD - computer aided design), to control industrial processes (PLCs - programmable logic controllers), to inspect parts (industrial vision systems), to automate material handling and certain repetitive tasks (industrial robots), to operate machine tools (CNC - computer numerical control), and to integrate processes and systems (CIM - computer integrated manufacturing). Engineers are challenged to understand these technologies and their strengths and weaknesses, and apply them in a cost-effective manner. It is also very important that these technologies be integrated to maximize their effectiveness.

       In 1991, this author joined St. Ambrose University and was assigned to teach the course IE375 – Computer Aided Manufacturing Systems. The school’s industrial engineering program was seeking ABET accreditation, and the department was carefully reviewing all courses to determine how to meet ABET guidelines. Two aspects of ABET guidelines, the course’s “design” content and course integration, were of most interest. Many years of industrial experience with computer-based technologies prepared the author to teach this course. IE375 had been previously taught by an adjunct professor. With the author being new to the teaching

1

profession, the challenge was to decide the best and most interesting way to deliver the course, considering ABET guidelines and working with existing materials and lab equipment.

      The designated textbook was by Groover [1]. Lack of time to investigate other books led to its continued use. The department lab equipment consisted of three 486/33 PCs, a Light Machines Corporation CNC milling machine (see Figure 1) with its own 286/12 PC, and a Microbot TeachMover industrial robot (see Figure 2) with teach pendant and Apple II computer. Someone had donated a General Electric Series One Junior programmable controller, without documentation. For software, the three lab computers had Microsoft’s WindowsTM 3.1, Autosketch®, spectraLightTM Mill, and spectraCAMTM (the latter three were all provided by Light Machine Corporation). Autosketch, from Autodesk, was a significantly scaled down version of the product AutoCADTM. Very good documentation existed for the operation of the milling machine [2] [3] [4] [5], and minimal documentation existed for the industrial robot [6]. All equipment and software were tested, and course development began.

Figure 1. Light CNC Milling Machine

Course Objectives and Development

      “Computer aided manufacturing” had to be defined for the industrial engineering profession. What do IE’s need to know about this topic? The catalog description was written as “Theory of feedback control systems and computer control of processes. Classroom, laboratory and field experiences in NC, DNC, CAD/CAM and robotics.” was vague, allowing a professor to define and develop the course in many conceivable directions. The course, as it had been taught, concentrated on CNC programming, motors, and mechanisms. Although the design of automation components is extremely interesting, the topics appeared much more appropriate to mechanical engineering than to industrial engineering.

      It was decided that, for industrial engineers, an understanding of the variety of computer-aided devices and their role in improving company productivity, quality, and cost was most important. These improvements occur with the successful application of correct technology. Understanding the capabilities, advantages, disadvantages, and integration of the technologies appeared most important.

       The course syllabus now states the objective as “to provide students in industrial engineering a knowledge and an ability to apply computer-aided manufacturing technology as a

2

cost-effective strategy. NC, CNC, CAD/CAM, robotics, vision systems, PLC's, and other technologies will be investigated and their applications explored. Strategic implementation, optimization, and systems integration issues will be addressed. Laboratory assignments will be used to emphasize important technological issues and provide hands-on design experience with the technologies.” The specific computer-based technologies chosen were: computers and networks, CAD, NC/CNC/DNC, CAM, robotics, automated inspection and vision systems, PLC’s, sensors, FMS, automated assembly systems, CAPP, and automated material handling.

Figure 2. Microbot TeachMover Robot

      Two problems immediately faced were: 1) a textbook covering all these topics did not exist, and 2) these technologies were rapidly changing. Groover’s book, although slightly outdated, did cover many of these topics. Supplemental sources from other books [7] and periodical articles were found for topics not covered in the book. Periodical articles provided contemporary information about application of the technology and updated information from the textbooks.

      The course was divided into two components, lectures and labs, giving each approximately the same amount of time. Lectures were presented in a conventional method, focusing on the technology components, application, advantages, and disadvantages. Laboratory assignments reinforced lecture material, and are further explained below. Grading was distributed as follows: Exams - 45 percent, laboratory assignments - 40 percent, attendance and assignments, 15 percent. Exam questions focused primarily on lecture information, but could include questions about laboratory knowledge.

Lab assignments

      Six laboratory assignments were used to reinforce lecture information and to give hands-on design experience. It is believed that hands-on experience is required when learning about computer-based technologies. Having students experience old (manual) ways of accomplishing manufacturing tasks, new computer-based approaches, testing and simulating computer results, and producing final operations, were believed to be important. Giving students exposure to several technologies, yet having a common theme across all laboratory assignments was also important. This could have been accomplished with the industrial robot, or even the PLC; but the author chose to use the CNC milling machine since it was the most expensive lab equipment

3

and using it could accomplish the goals. One major concern was that the author had never personally programmed CNC equipment, so this technology had to be learned.

      Open-ended laboratory assignments were developed that offered adequate opportunity for students to use design ideas and creativity. The assignments begin with simple concepts and become more complex – using experience from all previous laboratory assignments. The final lab integrates experiences from previous labs. Although laboratory assignments use a small subset of manufacturing technologies, they were designed to address general technological design and integration issues. Additional time away from normal class time may be needed by students to complete a project. Students were allowed to work in small groups, but each is encouraged to think through the problem. It is important that students explain their approaches, particular problems, and learning experiences. Some assignments include extra credit activities.

      Each student submits a professionally written report for each lab. Report guidelines [8] and an example report are provided. The reports are graded according to effort exerted, knowledge gained, and results. Determining which students are really doing the labs and who are not has been relatively easy. Several exam questions about the labs are included on exams.

Lab 1 - Computers and Operating Systems

      This lab exposes students to the computer and to different operating environments. A computer is dismantled and the components discussed. Operating systems and their varations among different manufacturing equipment is discussed. Common computer operations, such as creating files, viewing file contents, editing files, copying files, and deleting files are explored.

      The lab computers are connected to other networked computers. From the lab computers, DOS, UNIX, Novell, and Windows operating environments can be illustrated. Students are challenged to create files in one environment and move them to others. The importance of the ASCII text file is explained. Lastly, students learn about networks and how to e-mail files to the professor.

Lab 2 - Computer Aided Design

      Students are introduced to CAD and the electronic drawing – the beginning of many computer-based manufacturing technologies. Students use several CAD products, including AutoSketch [Error! Bookmark not defined.], Cadkey® [9], and Surfcam® [10]. The major goals are: to provide an overview of 2D and 3D design concepts and software; to provide practice designing parts; to understand that there are differences between CAD products in their presentation and use; to introduce CAD industry standards, file compatibility and file conversion issues; and to expose students to file translations.

      Students are expected to complete several tutorials. An example of one tutorial’s CAD drawing is shown in Figure 3. Students also try to transfer the drawing files over to the other CAD systems using DXF, IGES, and other file formats.

Lab3 - Robot Fundamentals and Programming

      This lab introduces students to the industrial robot (shown in Figure 2), which is another example of a computer controlled industry device. Students program the robot using a teach method – guiding the robot from point to point and recording the progressive steps. Students later learn that a teach method, although easy to perform, has some major productivity drawbacks.

4

       Students design an assembly operation, explore robot performance optimization techniques, and gain an understanding of the advantages and disadvantages of manual programming. Students can videotape the results for extra credit.

             Figure 3. CAD Drawing Produced with Autosketch Lab 4 - Process Planning and NC Parts Coding

      This lab introduces students to manual NC parts coding. Students must design the NC code for the part drawing shown in Figure 4. Students are directed to use a 3/16" diameter cutting tool, machinable wax as the material, and to set feeds and speeds to realistic values. Machining techniques and process planning are introduced, and the students must submit an acceptable process plan that includes an estimate for machine time.

      Using an editor of choice, students create the NC code required to machine the part on the Light milling machine. This file is saved as an ASCII text file. Students submit their NC programs to the professor via e-mail.

Figure 4. USA Star

Lab 5 - Simulation and CAD/CAM Programming

       Most computer generated code that will control manufacturing equipment must be tested before producing parts or initiating equipment action. Students use a software product called 3-D

5

Solid Verification [11], to simulate (animate) their NC code created in lab 4. When their code does not operate properly, they must decide how to debug and fix the code.

      Students then learn how to use CAM software to create the same part. The part is drawn with CAD software, the file is converted to DXF format and imported into spectraCAM software [12], the code is post-processed for the Light milling machine, NC code is created, and the code is tested with the 3-D Solid Verification software. An understanding of the advantages and limitations of CAM and simulation software is obtained. Students compare the CAM generated code with their manually created code.

Lab 6 - Part Design and Production on CNC Milling Machine

      Students have the opportunity to use knowledge gained throughout the previous laboratory assignments to manufacture a product. The knowledge includes designing parts with CAD, creating NC code with CAM, testing and verifying the NC code with simulation, and machining the part on the Light CNC milling machine (see Figure 1). Students learn to operate the Light CNC milling machine and execute the NC code. Proper machine safety procedures are also learned.

       Students machine two parts: USA Star, which was created in previous assignments, and a second part shown in Figure 5. After creating the CAD drawing, the drawing is imported into spectraCAM (see Figure 6). The cutting path is then generated (see Figure 7). Finally, the NC code is generated, tested in 3-D Solid Verification, and a part is machined on the Light CNC milling machine. The final part is shown in Figure 8.

Figure 5. Second Part to Manufacture

      Students are asked to compare actual machine times with estimates and explain any differences. Students attempt to optimize their code for minimum machine time. An integrated design challenge is presented for extra credit where students can create an operator incentive standard, develop a process plan, calculate production cost, and discuss quality control issues about the manufacturing process.

6

Figure 6. CAD Drawing Imported into CAM Software

Figure 7. NC Toolpath Generation

Figure 8. Final Part Produced on Milling Machine

Continuous Improvements

       Keeping a course related to computers current is an ongoing challenge. When operating on a small budget and using various funding methods to acquire supplies, it was found that only a

7

few improvements could be made each year. Making improvements each year has created “continuous improvement” for the course.

      For example, the original software was found to be outdated and was was immediately upgraded using department funds. A goal of equipping the lab with modern CAD/CAM software led to purchasing new products. Educational copies of Cadkey, Surfcam and 3-D Solid Verification were purchased with funds obtained internally by a “Faculty Development” grant. The grant provided an incentive to develop lab assignments, upgrade software, and purchase new software.

      In 1997, a grant from the Society of Manufacturing Engineers Education Foundation [13] provided additional copies of Cadkey and Surfcam. In addition, in 1997, an internal “technology focused” grant provided several copies and training for a newer CAD product – SolidworksTM [14]. This grant, under this author’s encouragement, was pursued by another faculty member who taught Engineering Graphics. The new copies of Cadkey, Surfcam, and Solidworks allowed the department to evaluation the products and determine its intended direction with CAD/CAM.

      Solidworks required Windows95TM; therefore, several lab computers had to be upgraded. This was accomplished with department funds. The department’s approach to upgrading computers was to do so with minimum investment. Realizing that computer technology becomes obsolete every two to three years, it makes sense not to spend more than is necessary on lab computers. The department chose to upgrade the motherboard with a fast, but less expensive, 200 MHz Cyrix-based board. 32MB of RAM and a 4MB graphics card were added, but the existing monitor, hard drive, floppy drive, and network cards were retained. Using this upgrade path, the cost was kept to below $500. Our experience with these computers has been very positive.

      The PCs have undergone upgrades. Our approach has been to upgrade components when possible and to utilized low cost suppliers. It is our belief to not spend money on brand name equipment because computer technology becomes quickly obsolete. Computer upgrades are accomplished from department funds.

Observations

      Course reviews by students were very positive. The benefits of an active learning model are derived. Some students complained about the extensive report writing, and the time involved with the lab assignments, but many commented positively about their knowledge gained. Students commented that the enjoyed working in the lab. Many students, at the beginning of the semester, do not believe that they are going to learn enough to machine parts from NC code by the end of the semester.

      One highlight of the course has been a tour of Genesis Systems Group – a local welding robotics systems company [15]. During this tour, students saw many technologies learned in the class in action. Genesis Systems Group has provided employment opportunities for the graduates.

      An additional benefit to students was that they could claim on their resumes that they had experience with computer operating systems, CAD, CAM, robotics, simulation, and NC programming.

Future Development

       All St. Ambrose University students are required to take several “writing-intensive” courses. This course, due to the nature of the lab reports, is a prime candidate to become a writing-intensive course. Several student reviews have reinforced this idea.

8

      A grant pre-proposal to the Society of Manufacturing Engineers Education Foundation has been submitted to upgrade and add several computers to the lab and to encourage greater course integration. Additional copies of Solidworks and Surfcam and a new CNC lathe are included in the grant. The activities in this grant will be coordinated with local industry.

      Solidworks, which is now being introduced to students in Engineering Graphics, will be used to design 3D solid models of parts, similar to the one shown in Figure 9. Solids modeling future is very strong. Surfcam is planned to completely replace the Light Corporation CAM software since it can generate NC code an perform simulations (see Figure 10). Eventually, parts with true 3D geometry will be included in the lab assignments and machined by Surfcam, as illustrated in Figure 11.

Figure 9. 3D Rendered Solid Model Produced by Solidworks

Figure 10. 3D Machined Part in Surfcam

      Other computer-based products, such as PLC’s, industrial vision systems, digital gages, sensors, and conveyor systems, may eventually be acquired and included in laboratory assignments. Upgrading the existing robot may be considered, but the current robot does offer a significant benefit in that its cable driven design makes it very safe to operate without supervision.

       A continuing challenge for this course is to find a textbook that appropriately addresses the chosen topics. Groover’s book, which was quite comprehensive, was getting outdated (copyright 1987). Singh’s book [16], published in 1996, was eventually chosen for its more

9

current copyright, but its coverage of the topics was still not satisfactory. Until a better textbook is found, the textbook will be supplemented with periodical articles.

Figure 11. 3D Part, Simulated Machining in Surfcam

      Lastly, a challenge to better integrate this course with other IE courses remains. Courses being considered include the following: Engineering Graphics, Problems Solving with Microcomputers, Manufacturing Materials and Processes, Industrial Engineering Methods, Design Fundamentals for Industrial Engineers, Engineering Economy, Quality Control and Reliability, and System Integration and Design.

References

1. Groover, M.P., Automation, Production Systems, and Computer-Integrated Manufacturing, Prentice-Hall, Englewood Cliffs, New Jersey, 1987.

2. SpectraLIGHT Mill System User’s Guide, Light Machines Corporation, Manchester, New Hampshire, 1993.

3. CAD/CAM/CNC Milling Tutorial, Light Machines Corporation, Manchester, New Hampshire, 1992.

4. An Introduction to CNC, Light Machines Corporation, Manchester, New Hampshire, 1992.

5. Conner, F. L., The Student Edition of Autosketch Version 3, Addison-Wesley Publishing Company, Inc., Reading, Massachusetts, no date.

6. Microbot TeachMover Robot Programming Manual, Microbot, Inc., Mountain View, CA, 1982.

7. Chaplin, J.W., Instrumentation and Automation for Manufacturing, Delmar Publishers Inc., Albany, New York, 1992.

8. Hubbard, W., Flynn, E.A., Barna, B.A., et. al., Manual for Report Writing in Engineering Design, Michigan Technological University, 1992.

9. CADKEY97 Reference Manual, Baystate Technologies, Marlborough, Massachusetts, 1997.

10. Surfcam CAD/CAM Systems, Surfware, Inc., Westlake Village, California, 1996.

11. 3-D Solid Verification, Light Machines Corporation, Manchester, New Hampshire, 1994.

12. spectraCAM Milling V3.1, Light Machines Corporation, Manchester, New Hampshire, 1993.

10

13. Society of Manufacturing Engineers Education Foundation, Dearborn, Michigan,

http://www.sme.org/smeef/smeefhome.html.

14. SolidWorks97 User’s Guide, SolidWorks Corporations, Concord, Massachusetts, 1997.

15. Genesis Systems Group, Davenport, Iowa.

16. Singh, N., Systems Approach to Computer-Integrated Design and Manufacturing, John Wiley & Sons, Inc., New York, 1996.

RICHARD JERZ

       Rick Jerz is an Assistant Professor of Industrial Engineering at St. Ambrose University in Davenport, Iowa, where he has interest in teaching manufacturing and computer related courses. He has an undergraduate degree is from Illinois Institute of Technology, an MBA from St. Ambrose University, and a Ph.D. from The University of Iowa. In 1995 he was awarded a predoctoral fellowship from the United States Department of Energy (DOE) in “Integrated Manufacturing.” He has over fifteen years manufacturing engineering experience, primarily with John Deere.

11

Student Solutions Manual For Calculus With Applications And Calculus With Applications, Brief Version By Margaret L. Lial

READ ONLINE 

We have made sure that you find the PDF Ebooks without unnecessary research. And, having access to our ebooks, you can read by Margaret L. Lial Student Solutions Manual For Calculus With Applications And Calculus With Applications, Brief Version online or save it on your computer. To find a Student Solutions Manual For Calculus With Applications And Calculus With Applications, Brief Version, you only need to visit our website, which hosts a complete collection of ebooks.

the illustrated history of the schickel motorcycle 1911-1924, hildegard of bingen and musical reception: the modern revival of a medieval composer, words well spoken: george kennedy's rhetoric of the new testament, seidways:

shaking, swaying and serpent mysteries, a shade of kiev, the ecology of modernism: american environments and avant-garde poetics, minimum wage volume 1: focus on the strange, verbal workout for the gmat, 2nd edition, gypsy in my soul clay boland 1937 sheet music sheet music 223, origin of development of calendars in the world, arctic fox: very cool!, the map thief: the gripping story of an esteemed rare-map dealer who made millions stealing pri celess maps, misery bay: an alex mcknight novel, beginning blender: open source 3d modeling, animation, and game design, the centennial celebration of general sullivan's campaign against the iroquois in 1779: held at waterloo, september 3rd, 1879, the invention of wings: a novel, the ties that bind series collection: steamy lesbian sex!, the daguerreotype, automated systems based on human skill, bud the crud and the vampire-werewolf wars, the allergy epidemic: a mystery of modern life, adhd look-alikes : other reasons children , flit, squirm, distract, and just space out, aufgabensammlung elektrotechnik 2: magnetisches feld und wechselstrom. mit strukturiertem kernwissen, lösungsstrategien und -methoden, high speed diode lasers, the rough guide to the grand canyon 1, diario de un escritor, vintage textured barkcloth, aepa professional knowledge- secondary secrets study guide: aepa test review for the arizona educator proficiency assessments, tallinn manual on the international law applicable to cyber warfare, bundle: finite mathematics, enhanced edition , 7th + enhanced ... access card for one term math and science, jaguar xxr coupe y convertible 2003. .: an article from: automundo magazine, poems, the spirit of jesus in scripture and prayer, 2011 college access and opportunity guide, mexican cooking class cookbook, a newbie's guide to iphone 6 and iphone 6 plus: the unofficial handbook to iphone and ios 8, a tooth is loose, saint martin de porres: humble healer, the mystery of silver falls, morgana - el camino naranja: la novela espiritual que marcar, zion national park: utah, usa, iso 1043-3:1996, plastics - symbols and abbreviated terms - part 3: plasticizers, los secretos de osiris = the secrets of osiris, legoland florida for adults: 12 tips to enjoy your trip, the essential frank sinatra: easy piano/vocal, white male privilege: a study of racism in america 50 years after the voting rights act, the misanthrope: stone's story, dragonfly stories: tales of the erotic and strange, private eyes - acting edition, an infectious brain disease of horses and mules, penthouse: entre las sabanas: una coleccion de historias eroticas, recovery options: the complete guide, a pregnant pause, espectacular de lucha libre, sacred space: the quest for transcendence in science fiction film and television, the women at menopause, mounted by a monster: the complete werewolf stories, fodors-belgium'89, seduction of suicide: understanding and recovering from addiction to suicide, the lizard man speaks, belize: selected proceedings from the second interdisciplinary conference, ghost cop tp, the official parent's sourcebook on retinoblastoma: a revised and updated directory for the internet age - common, the world of the khazars, nureyev: his spectacular years, law dictionary for laymen, "i can't stop babying you" sheet music, kaplan gmat verbal workbook, 5th ed, accounting information systems: concepts and practice for effective decision making, satie remembered paperback

student solutions manual for calculus : early transcendental student solutions manual lial calculus and student solutions manual for calculus: robert t book supplements - stewart calculus pearson - calculus with

applications, 10/e - margaret l. lial student solutions manual for calculus with appl complete solutions manual (10th edition) | department of student solutions manual , multivariable for calculus and calculus with applications, brief version, 10th edition pearson - calculus with applications, brief Student Solutions Manual for Calculus with Applications and Calculus with Applications, Brief Version by Margaret L. Lial pdf student solutions manual for stewart\'s single student solutions manual for calculus , early transcendentals calculus with applications solutions manual student solutions manual for larson/edwards student solutions manual for finite mathematics download calculus with applications brief version student solutions manual for calculus: early student solutions manual for calculus with calculus with applications, brief version, 10th, lial student solutions manual single variable for thomas' calculus Student Solutions Manual for Calculus with Applications and Calculus with Applications, Brief Version by Margaret L. Lial pdf student solutions manual for calculus and its calculus with applications, 10th edition - mypearsonstore student solutions manual for calculus with student solutions manual for calculus, 9th student solutions manual for stewart's calculus with applications, brief version plus student solutions manual, volume 2 (chapters calculus solutions manuals | chegg.com - chegg - save up to calculus with applications 10th edition solutions precalculus solutions manuals | chegg.com Student Solutions Manual for Calculus with Applications and Calculus with Applications, Brief Version by Margaret L. Lial pdf calculus with applications and calculus with student solutions manual for multivariable student- solutions- manual-single-variable- calcu calculus with application brief with student calculus with applications, brief version 10th edition pearson - student solutions manual for calculus, student solutions manual for stewart's single lial calculus with applications solutions manual student solutions manual, multivariable, for thomas' calculus student solutions manual: to accompany calculus Student Solutions Manual for Calculus with Applications and Calculus with Applications, Brief Version by Margaret L. Lial pdf

Related phrasal:

The Illustrated History Of The Schickel Motorcycle 1911-1924, Hildegard Of  Bingen And Musical Reception: The Modern Revival Of A Medieval Composer, Words Well Spoken: George Kennedy's Rhetoric Of The New Testament, Seidways:  Shaking, Swaying And Serpent Mysteries, A Shade Of Kiev, The Ecology Of  Modernism: American Environments And Avant-garde Poetics, Minimum Wage  Volume 1: Focus On The Strange, Verbal Workout For The Gmat, 2nd Edition, Gypsy In My Soul Clay Boland 1937 Sheet Music Sheet Music 223, Origin Of  Development Of Calendars In The World, Arctic Fox: Very Cool!, The Map  Thief: The Gripping Story Of An Esteemed Rare-map Dealer Who Made Millions  Stealing Pri Celess Maps, Misery Bay: An Alex Mcknight Novel, Beginning  Blender: Open Source 3d Modeling, Animation, And Game Design, The Centennial  Celebration Of General Sullivan's Campaign Against The Iroquois In 1779:  Held At Waterloo, September 3rd, 1879, The Invention Of Wings: A Novel, The  Ties That Bind Series Collection: Steamy Lesbian Sex!, The Daguerreotype, Automated Systems Based On Human Skill, Bud The Crud And The Vampire-werewolf Wars, The Allergy Epidemic: A Mystery Of Modern Life, Adhd Look-alikes : Other Reasons Children , Flit, Squirm, Distract, And Just Space Out , Aufgabensammlung Elektrotechnik 2: Magnetisches Feld Und Wechselstrom. Mit Strukturiertem Kernwissen, Lösungsstrategien Und -methoden, High Speed Diode

Lasers, The Rough Guide To The Grand Canyon 1, Diario De Un Escritor, Vintage Textured Barkcloth, Aepa Professional Knowledge- Secondary Secrets  Study Guide: Aepa Test Review For The Arizona Educator Proficiency  Assessments, Tallinn Manual On The International Law Applicable To Cyber  Warfare, Bundle: Finite Mathematics, Enhanced Edition , 7th + Enhanced ...  Access Card For One Term Math And Science, Jaguar Xxr Coupe Y Convertible  2003. .: An Article From: Automundo Magazine, Poems, The Spirit Of Jesus In  Scripture And Prayer, 2011 College Access And Opportunity Guide, Mexican  Cooking Class Cookbook, A Newbie's Guide To Iphone 6 And Iphone 6 Plus: The  Unofficial Handbook To Iphone And Ios 8, A Tooth Is Loose, Saint Martin De  Porres: Humble Healer, The Mystery Of Silver Falls, Morgana - El Camino  Naranja: La Novela Espiritual Que Marcar, Zion National Park: Utah, Usa, Iso  1043-3:1996, Plastics - Symbols And Abbreviated Terms - Part 3: Plasticizers  , Los Secretos De Osiris = The Secrets Of Osiris, Legoland Florida For  Adults: 12 Tips To Enjoy Your Trip, The Essential Frank Sinatra: Easy Piano/vocal, White Male Privilege: A Study Of Racism In America 50 Years  After The Voting Rights Act, The Misanthrope: Stone's Story, Dragonfly Stories: Tales Of The Erotic And Strange, Private Eyes - Acting Edition, An  Infectious Brain Disease Of Horses And Mules, Penthouse: Entre Las Sabanas:  Una Coleccion De Historias Eroticas, Recovery Options: The Complete Guide, A Pregnant Pause, Espectacular De Lucha Libre, Sacred Space: The Quest For  Transcendence In Science Fiction Film And Television, The Women At Menopause  , Mounted By A Monster: The Complete Werewolf Stories, Fodors-belgium'89, Seduction Of Suicide: Understanding And Recovering From Addiction To Suicide  , The Lizard Man Speaks, Belize: Selected Proceedings From The Second Interdisciplinary Conference, Ghost Cop Tp, The Official Parent's Sourcebook On Retinoblastoma: A Revised And Updated Directory For The Internet Age -  Common, The World Of The Khazars, Nureyev: His Spectacular Years, Law Dictionary For Laymen, "i Can't Stop Babying You" Sheet Music, Kaplan Gmat  Verbal Workbook, 5th Ed, Accounting Information Systems: Concepts And Practice For Effective Decision Making, Satie Remembered Paperback 

Int. J. Social Research Methodology

Vol. 9, No. 5, December 2006, pp. 379–391

Software and Method: Reflections on

Teaching and Using QSR NVivo in

Doctoral Research

Lynne Johnston

ylorSRM_A an

Received 26 October 2004; Accepted 23 June 2005

950000DeceLynneJh.johston@acnternation&

This reflective paper draws on a range of experiences developed over the last 11 years

06TaylorOriginal364-557901080/1370Ar Fst)/urn ch Me

regarding the way in which qualitative data analysis (QDA) software (QSR NUD*IST and NVivo) is taught and used within doctoral research. The existing separation of qualitative methods training from QDA software training can result in disconnected technical and methodological learning curves. This can cause a number of problems for doctoral students because a ‘methods revolution’ is being experienced and current students are not necessarily exposed to the support they require via the methods literature, their postgraduate training programme or their supervisor. Three key influences on the use of QDA software are discussed within the context of teaching and learning QSR NVivo: the increased popularity of QDA software amongst those from traditionally positivistic backgrounds; the promise of improved levels of transparency; and the reliance upon the free tutorials, which are distributed with the software, to learn qualitative research methods as well as software processes. Implications for doctoral students, supervisors and examiners are discussed.

My Story

I first became involved in computer-assisted qualitative research in 1994, when I considered doing some interviews to supplement the main quantitative study in my doctoral research. I was located in the Science Faculty of a traditional United Kingdom (UK) university under the supervision of a chartered health psychologist. The only colleagues engaging with qualitative research were some clinical psychologists; none had any experience of using a qualitative software package. I decided from the outset

Correspondence to: Lynne Johnston, School of Neurology, Neurobiology and Psychiatry, Newcastle University, 4th Floor, Ridley Building, Newcastle Upon Tyne, NE1 7RU, UK. E-mail: lynne.johnston

ISSN 1364–5579 (print)/ISSN 1464–5300 (online) © 2006 Taylor & Francis

DOI: 10.1080/13645570600659433

380 L. Johnston

that I would use a computer program to facilitate my analysis. I referred to Miles and Huberman (1994) and decided to select QSR NUD*IST (version 3).

  I viewed qualitative analysis in much the same way as I did in quantitative study, i.e. as a separate phase to data collection. It never occurred to me that this should be an iterative process (Johnston, Corban, & Clarke, 1999) or that I could use the software to assist with the organization and integration of my literature review (Bringer, Johnston, & Brackenridge, 2004; di Gregorio, 2000). I never considered that my use of software would be questioned in any way (Richards, L., 2002) or that I would need to spend considerable time and valuable word space explaining the background and use of qualitative data analysis (QDA) software in my thesis, viva and resultant articles (Johnston & Carroll, 1998a, 1998b; Johnston et al., 1999). I never imagined that I would invest so much time learning the technical aspects of the software, or that I would squander a considerable amount of this time doing irrelevant things with it. I failed to recognize that I had fallen into a coding trap (di Gregario, 2003a, 2003b; Gilbert, 1999, 2002; Richards, L., 2002) and I never discussed the idea of keeping a research journal to help document the processes involved, or to write and link memos to assist with my audit trail (Bringer et al., 2004; di Gregorio, 2003a, 2003b). It never even occurred to me that keeping archived copies of the project to refer back to might aid the writing-up process (Bringer et al., 2004). Towards the end of my doctoral research, NUD*IST version 4 was launched and I attended a training course with the software developer (Lyn Richards). It was at this point that I discovered my ignorance regarding the skilful use of the software. More importantly, I discovered how much I did not know about qualitative research.

  In the last eight years, I have delivered training courses in NUD*IST and NVivo to academics, policy makers and research groups throughout the UK and internationally. I have attended several training sessions with the software developers,1 and spent time at a specialist research retreat.2 During this time I have met literally hundreds of qualitative researchers from a range of countries and subject disciplines.

  In the majority of my training courses the participants have been studying for a higher degree, usually a doctorate. On a minority of occasions the student’s supervisor has also attended. Over the last eight years I have witnessed a growing demand for training in university departments which have traditionally eschewed qualitative research. This pattern of adoption and use has been recognized and discussed elsewhere (Fielding & Lee, 2002). I have also found that my approach to teaching has increasingly moved away from the technical aspects of the software towards an integration of software processes and qualitative methods. I have found that researchers are eager for information on the impact of computing on methods. As a research degree supervisor and examiner I have witnessed examples of successful and unsuccessful QDA software use. Some students have used the software in innovative and creative ways and the thesis has arguably been improved as a result (see e.g. Bringer, 2002); others whom I have examined have not used the software effectively.

  L. Richards (2002) called for more debate, honest reflection and discussion on the impact of qualitative software packages on the way in which we actually do qualitative research. There are lots of different software programs on the market which can assist

International Journal of Social Research Methodology 381

with qualitative data analysis. This paper focuses specifically on the use of NVivo3 within doctoral research. The reader is referred to Delamont, Aitkinson, and Parry (2004) for a discussion of wider issues in the PhD supervision process, and to Bazeley and L. Richards (2000), Morse and L. Richards (2002) and L. Richards (1999b, 2005) for information on the use of NVivo more generally.

Technical and Methodological Learning Curves

It is true to say that there is a ‘technical learning curve’ with any new software; with QDA software programs is it clearly also true to say that there is a ‘methodological learning curve’ involved, because technology has revolutionized the way in which researchers now approach qualitative data analysis (L. Richards, 2002). The problem for many current doctoral candidates is that they are finding themselves increasingly ensnared in this ‘methods revolution’ without access to an informed research methods literature, integrated research training programmes or a well-versed supervisor.

  Typically, the students who attend my training sessions are at quite an advanced stage in the doctoral process, because they (and their supervisors) do not consider the issue of software training until too late in the process (as they might do with SPSS). The majority will have completed their initial literature review and will have started and occasionally completed their data collection before they actually engage with the software. In some cases, participants have already conducted a considerable amount of analysis using manual methods or with the aid of Microsoft Word. This is extremely unfortunate because the software can, and arguably should, be used from the beginning of the research process (see L. Richards, 2005, for a discussion).

  In my experience in the UK, it is common for students to start a doctoral thesis without having a detailed knowledge of qualitative analysis methods. In many cases students complain that their supervisor(s) also has a lack of knowledge of qualitative research processes or a lack of knowledge of, or a resistance to, the use of a specific software program. Resistance to the use of QDA software is often fuelled by an outdated research methods literature, which is still dominated by discussions about the relative pros and cons of various software programs. Fielding (2002) correctly asserts that this is because QDA software programs are still not viewed as integral to the analysis process; as a result, current methods texts still include separate chapters on software, suggesting a false dichotomy between ‘tool’ and ‘process’ (see e.g. Weitzman, 2003; Willig, 2001). For those embracing Glaser’s Grounded Theory (GT) perspective this is no doubt aggravated by his scathing and misplaced critique of computer-assisted approaches to GT analysis (Glaser, 2003).

  Most of the existing literature examining the impact of software on the way we do qualitative research has been written either by the software developers (see e.g. Bazeley & L. Richards, 2000; Morse & L. Richards, 2002; L. Richards, 1998, 1999a, 1999b, 2000, 2002) or by people involved in software training and consultancy (see e.g. Bazeley, 2002, 2003a; di Gregorio, 2000, 2003a, 2003b; Jackson, 2003). Reflective reports about the way in which computing has influenced the way in which we do qualitative research are still largely confined to specialist conferences on qualitative computing, such as the

382 L. Johnston

QSR Strategies Conference Series.4 In the UK, funding for attendance at conferences is usually on the condition that research students are presenting their work. Thus, many UK-based research students are not funded to attend such specialist conferences until it is too late in the doctoral process.

  The Economic and Social Research Council (ESRC) inadvertently contributed to this false dichotomy between software and methods training when they issued their research training guidelines for postgraduate students (ESRC, 2001). These guidelines fail to emphasize the need for an integration of technology and methodology within postgraduate methods training. As a consequence, it is not unusual for university departments either to send postgraduate students for specialist training (e.g. the ESRC-funded CAQDAS Networking project5) or to buy in specialists trainers in qualitative data analysis to teach specific software packages.

  I have been bought in to many different universities within the UK over the last few years to provide specific software training. It is impossible to teach students how to use the technical aspects of the software without talking about qualitative methods or to discuss the impact that software has had on the way we do qualitative analysis. Students need to fully understand the ‘methods revolution’ (L. Richards, 2005) and are eager for information on this. The challenge of combining discussions about methodology and teaching the functional aspects of the software is a difficult one and an initial literature is starting to emerge on this topic. Jackson (2003) reports that in the United States (US) she is also bought in to deliver short-course training sessions to a number of universities. In her article she provides some useful guidance on blending technology and methodology within the context of short-term training courses.

  Carvajal (2002) is critical of the short-course approach to training and argues that traditional research methods courses need to be changed to ensure software use is fully integrated into the programme. In his analysis of a number of training workshops advertised via the QUAL-Software e-mail discussion group he noticed that most were one-day sessions, prerequisite knowledge of qualitative methodology or methods was typically not required, all workshops were advertised as hands-on yet participants were typically working on someone else’s data, and the majority focused on the technological rather than the methodological aspects. University departments need to consider whether or not a short-course training workshop is sufficient or whether qualitative methods and software training should be fully integrated as part of a doctoral student’s research training programme.

  Differences between the doctoral system in the UK and the US would suggest that integration may be easier to achieve within the US system because of the increased emphasis on research training within the US system. This is reflected in the level of interest shown in the US in the international conference dedicated to Teaching Qualitative Methods Using Qualitative Software.6 Davidson (2004) recently presented three case examples to demonstrate how she integrated NVivo into her semester-long research methods programme for doctoral students in the US. She highlighted a number of tensions associated with grading a student’s performance and pointed out that ‘understanding how qualitative research software works and understanding how

International Journal of Social Research Methodology 383

to teach it are relatively but distinctly different forms of knowledge’ (Davidson, personal communication, 2004).

  A doctoral student’s lack of understanding regarding the integration of technology and methodology may be hindered further if their research degree supervisor is unfamiliar with both QDA software and the emerging literature regarding the ‘methods revolution’ (see e.g. di Gregorio, 2003a; Gilbert, 1999; Jackson, 2003; Marshall, 2002; L. Richards, 2002). Qualitative software has been publicly available for 21 years (L. Richards, 2004), yet there are no current requirements in the UK for doctoral supervisors or examiners to be trained in the use of QDA software. Is it acceptable for doctoral supervisors and examiners to know less about computer-assisted approaches to analysis and the current methods revolution than their students?

  One way that the novice NVivo user can speed up the technical learning, associated with the familiarization of the software functionality, is to use it as a management tool for the whole doctoral process, not simply the aspects that they initially view as data (e.g. transcribed interviews and focus groups, field notes). The most obvious things to include would be the student’s research diary, different types of memos and their literature review (see e.g. Bringer et al., 2004; di Gregorio, 2000). In her practical text entitled Handling Qualitative Data, L. Richards (2005) stresses the importance of using software from the earliest point in a project. If a student can see multiple uses in the program, they are arguably more likely to invest the necessary time required to learn its functionality. It is essential that doctoral supervisors recognize that this can be a time-consuming process and one that must begin early in the doctoral programme.

A Consequence of Lack of Integration: The Code and Retrieve Cycle

Qualitative researchers have in the past expressed concern about losing closeness to data (see e.g. Fielding & Lee, 1998; Weitzman & Miles, 1995). Yet, somewhat ironically, in examining the concept of closeness to data and software use, researchers have discovered that software can allow some users to get too close and this can lead to a code and retrieve cycle. NVivo trainers around the world (e.g. in the US: Gilbert, 1999; Jackson, 2003; in the UK: di Gregorio, 2003a; and in Australia: Marshall, 2002; L. Richards, 2002, 2005) have identified this. Researchers, particularly (but not exclusively) novice qualitative researchers, have found themselves coding in a somewhat mechanistic manner, often for excessively long periods of time, without using some of the in-built tools to help them to see the proverbial wood from the trees. This incessant desire to code every part of a document without taking time to think and reflect upon data can lead to an overly descriptive prosaic project.

  Gilbert (1999) conducted in-depth interviews with qualitative researchers who had experience of manual and computer-assisted methods of analysis and describes three levels of closeness to the data: the tactile–digital divide (working on screen verses paper), the coding trap (getting too close), and the metacognitive shift (reflection on processes). Gilbert explained that movement from each level was driven by a gradual adaptation towards confident software use. When users were able to reflect appropriately upon their software use (metacognitive shift), they were able to correct errors

384 L. Johnston

which had thwarted their progress at earlier stages (e.g. when they encountered the coding trap). Given the timing of Gilbert’s study, it is likely that the problem of the tactile digital divide has reduced with the normalization of software in our everyday lives.

  It is certainly true to say that computer software can facilitate and/or highlight the coding trap and the code and retrieve cycle, but I would suggest that there are three key influences here, as follows.

1. QDA software programs have arguably increased the popularity of qualitative research amongst those from traditionally positivistic backgrounds and they have brought with them different ways of approaching qualitative data analysis.

2. The transparency that comes with QDA software may have merely highlighted a problem that has always existed.

3. The free tutorials, which are distributed with the software, have systematically influenced the way in which people have used the software.

Heightened Popularity of Qualitative Research

QDA software has undoubtedly legitimized qualitative research in disciplines that have traditionally adopted quantitative approaches (see Fielding & Lee, 2002). This has been accompanied by a growing interest in mixed-methods approaches more generally in the social and behavioural sciences (see e.g. Tashakkori & Teddlie, 2003). One of the reasons for this may be the increased ability to link qualitative and quantitative data in a way that was extremely difficult to do without software.

  For example, importing tabular data from a statistical software package on things that you know you know about participants (document attributes) or cases (node attributes) can be incredibly useful when using NVivo’s powerful search tool to compare and contrast themes (Welsh, 2002). Using node and document attributes in this way can allow researchers to automatically filter out (via the creation of sets) certain people or themes on the basis of known characteristics. L. Richards (2000) has named this type of analysis ‘pattern analysis’, and suggested that many people who claim to be using versions of GT are in fact performing a form of pattern analysis. Seale (2002) conducted a review of published articles that mentioned the use of QDA software and found that in most cases the analysis was indeed a type of pattern analysis. This resulted in a lack of analytic depth and was criticized on the grounds of questionable credibility and trustworthiness.

  The developers of NVivo have also given significant attention to the ability to export detailed coding information. This offers the potential to create data sets from the qualitative data which may then be exported to a statistical program, the advantage being that the researcher can then go back to the original text to seek further interpretation (Bazeley, 2004). A recent review of over 200 published mixed-methods studies by Bryman (2004) revealed just seven which involved transformation of qualitative data to a quantitative form. In a recent presentation to the ESRC Research Methods Festival in the UK (a festival which is heavily subsidized and targeted towards doctoral

International Journal of Social Research Methodology 385

students), Bell (2004) provided a technical overview of how qualitative data can be linked to quantitative data. Regrettably, he failed to enter into any discussion about what these numbers actually meant or to adequately direct researchers to the existing literature (see e.g. Bazeley, 1999, 2002, 2003a, 2003b, 2004). Not only is there enormous scope for development in this area; there is also a need for sound theoretical consideration of the issues raised (Bazeley, 2004).

  Some aspects of QDA software programs, such as the ability to generate coding automatically or to search text for keywords, phrases or patterns of words, can save a considerable amount of time. However, the fact that software can assist researchers in searching text in this way does not justify the sole use of these tools within a qualitative study. Inductive techniques coupled with the strategic use of the search tool, document links, node links, the show tool and the modeller are required to gain a rich understanding of the data (see L. Richards, 2005, for a practical discussion).

  It is not unusual for qualitative researchers to talk about rigour within qualitative research via discussions of inter-coder reliability (see e.g. Kaczynski, 2003). For some, rigour may be conceptualized as consistency and completeness in coding. If this type of consistency is strived for, then it is certainly true that a range of tools within NVivo can facilitate the process (e.g. generating profile reports on nodes and documents, skilful use of the assay and show tools, matrix searching to generate coding tables, viewing nodes and documents with coding stripes etc.). However, a discussion of the impact of QDA software programs on the increased level of rigour within different methodological approaches has still to be had (L. Richards, 2004). If a mixed-methods approach to analysis is being pursued, it is particularly important for researchers to discuss how this fits with the methodological perspective they are adopting and to debate where, why and in what way rigour fits with their underpinning epistemological position.

Unprecedented Levels of Transparency: Has the Code and Retrieve Cycle Always Existed?

It may be the case that the ‘code and retrieve’ cycle has always existed and has simply been exposed as a ‘dirty secret’ via the use of QDA software (L. Richards, 2004). With manual methods there has traditionally been much more scrutiny of the final product (e.g. doctoral thesis) rather than the research processes involved in creating the final product. QDA programs such as NVivo provide a considerable potential to give unprecedented levels of transparency within qualitative research. For example, it is now possible for supervisors and examiners to view not only the data, but also what a student has done with that data and to track the processes involved in the whole research journey (e.g. browsing data, reading memos, viewing coding structures, reviewing links and annotations, exploring models, examining the research journal etc).

  A potential consequence of increased levels of transparency is that the expectations placed upon a current doctoral student may be greater than in the past. This means that the level of assessment in a thesis employing NVivo can be more rigorous. This level of transparency has historically been much easier to assess with quantitative research. In

386 L. Johnston

my own mixed-methods doctoral research, I was instructed to keep all my quantitative data and SPSS output files in case these were required by the examiners. However, the need to keep all my qualitative data only ever referred to my interview transcripts, not what I did with the data. Unfortunately, the use of QDA software has not brought with it the promised levels of transparency in practice. There is still therefore a void between the promised role of computer-assisted methods of analysis in improving the quality of qualitative research and current practices (Gibbs, Friese & Mangabeira, 2002).

  Spencer, Ritchie, Lewis, and Dillon (2004) were recently commissioned by the UK government to develop a framework to guide the assessment of the quality of qualitative research. This involved a review of the existing literature relating to standards in qualitative research, and interviews with government-based commissioners of research, representatives from funding councils and academics. The report highlighted four guiding principles: that research should be contributory, defensible in design, rigorous in conduct and credible in claim. Transparency was considered to be an essential feature of good research and was seen to involve an honest account of the way in which the research was conducted, a full description of sampling, data collection and analysis processes, and a candid discussion about the relative strengths and weaknesses of the study. Incongruously, this report makes no reference to QDA software programs, despite the obvious role that software can play in maximizing transparency (Bringer et al., 2004; Thompson, 2002).

  My own attempt to address the transparency issue has been to encourage doctoral students to write and present reflective accounts of their use of NVivo (see e.g. Bringer, Johnston, & Brackenridge, 2004, 2006; Coupland & Johnston, 2004; Jevon & Johnston 2001, 2003). In the UK, the doctoral viva offers the potential for a detailed discussion of the assessment of research processes as well as the research product (the thesis itself). It is arguably the research processes which are most transferable; paradoxically, they often remain invisible (Thompson, 2002).

The Impact of Demonstration Software on the Use of NVivo

The demonstration tutorials which are distributed with QDA software are incredibly useful aids to teaching and learning. However, they can also encourage novice researchers to use the software inappropriately. This is especially true when users attempt to use the demonstration tutorials as their sole method of support. New users tend to be highly motivated to learn the functionality of the software, yet do not necessarily acknowledge that each tutorial is specifically designed to teach software processes, not qualitative research methods per se. However, for some new users this may be their first real practical exposure to qualitative research. Thus, in teaching themselves how to use the software they are usually doing so with primarily the technical learning curve in mind.

  In my experience, most users report that they get to a certain point in a tutorial and then stop because they feel they know enough, or because they are bored, or because they are under an extreme time pressure to complete their analysis. For some this will involve stopping after they have learned how to code and retrieve. For students who are supervised and examined by those with experience of manual methods and no

International Journal of Social Research Methodology 387

exposure to software, this may be perceived as acceptable because it mirrors what the supervisor and examiner expect the software to do. In essence, new users may not know what they need to know because they are misinformed by their supervisors and/or not exposed to the appropriate methods literature via their research methods training programmes.

  The problem with the demonstration tutorials which accompany NVivo is that it is only when you move on to the later stages of the tutorials that you can see the full power and functionality of the software. As many of the tutorials are sequenced into different stages, new users often view the later stages as an ‘advanced’ stage of analysis. Conceptualizing the search functions in NVivo as advanced stages of analysis is simply not true or helpful (Gilbert, 2002). In Gilbert’s study of software use, she noted that is only when users become relatively expert with the program that they are able to gain distance on a metacognitive level (Gilbert, 2002). In essence, they cannot see what they are trying to do or how to break down a search into a series of logical steps, which build the results of preliminary searches onto the next search. This is analogous to the novice chess player who fails to think two or three moves ahead in a game. Or, if compared to quantitative analysis, it may be conceptualized as only doing descriptive statistics when multivariate analysis is required.

Some Things to Emphasis When Teaching QSR Vivo

In my experience, there are three key things that need to be emphasized when teaching NVivo (especially if teaching is heavily reliant on the demonstration tutorials): the importance and function of the research journal; the role of the free and tree node system and why certain trees structures will aid searching and why others will inhibit searches; and the need to gain analytical distance from data to avoid coding traps such as the code and retrieve cycle.

The Importance of the Research Journal

Encouraging a doctoral student to record key decisions, reflections, emergent ideas and hunches within a research journal can help them to gain the necessary analytical distance which is so often lacking in qualitative projects (Gilbert, 2002; Seale, 2002). The main benefit of keeping a research journal inside a program such as NVivo is that it encourages the researcher to rapidly and openly record their thoughts, questions, reflections and emergent theoretical ideas to a central executive point in the program. In essence it can act as a conceptual launch pad from which the researcher can then jump to specific points in their literature, data or memos to explain, conceptualize and theorize. In NVivo, the journal can be coded and searched, and linked to other documents via internal annotations, in-text doclinks and node links, and with node extracts.

  An electronic research journal can aid further interpretation and creativity, because it gives the person time to reflect, think, ask further questions, and try to explain or theorize about the data in a flexible way, without the fear of losing where they are in their project. I encourage doctoral students to use their research journal as a planning

388 L. Johnston

tool for supervisory meetings and to help them to write their reflections on the whole doctoral process. The feedback that I have received is that students find this enjoyable and relatively easy to write because their journey is already mapped out and contained in a central place. Ironically, the flexibility and creativity that this facility provides is the very thing Glaser (2003) appears to be so concerned about losing when he critiques the use of QDA software.

The Problem of Multiplicative Tree Structures

One of the most common errors that new users tend to make is that they view the index (tree) system as a way of modelling their theory, or expected thesis chapters, rather than viewing it as a functional infrastructure that can maximize the way the data are searched. Poorly organized tree structures include different types of concepts in the same tree and typically contain multiple repetitions of the same node in various places throughout the tree structure (T. Richards, 2004). When developing a child node it is helpful to ask: ‘Is this node a conceptually related and mutually exclusive sub-category of the node that I am planning to attach it to (the parent node)?’. A further question to consider might be: ‘Can I create a new node using the search tool functions by combing existing nodes or do I need to code up from the data interactively?’ (for a further discussion, see Bazeley & L. Richards, 2000; Morse & L. Richards, 2002; or L. Richards, 2005). Unfortunately, several of the demonstration tutorials which accompany the NVivo software actually violate some of these good-practice guidelines and show examples of inflexible and multiplicative coding systems. Thus is it no accidence that problematic index systems are so common in practice.

Gaining Analytical Distance to Maximize Searching

Demonstration tutorials do not sufficiently emphasize the inbuilt tools which can help a researcher to gain analytic distance from their data, or tools associated with an iterative approach to analysis. Under-utilized aspects include assay, the show tool, doc links and node links, because users often fail to see their purpose. One of the most under-used aspects of the search tool is the use of the ‘scope’ facility. Users fail to appreciate the importance of sets and how the scoping aspect of the search tool can help them to create sets. They also tend to rely heavily on intersect and matrix searching because they find it easier to conceptualize what this type of search is doing. Stepping back from the data and thinking logically about how to build and develop the results of searches into an iterative series of steps is at the heart of expert use of NVivo. It may be that those who have been traditionally attracted to qualitative research have a predisposition toward creativity rather than logic!

Conclusion

I have raised several pedagogic issues regarding the integration of software and method in the training of doctoral researchers. I have discussed some common problems and

International Journal of Social Research Methodology 389

influences associated with the use of NVivo software and offered some practical suggestions which may be incorporated into training. These issues could be usefully discussed and debated within postgraduate methods training programmes. Research degree supervisors need to engage with this debate.

Acknowledgements

This article is based on a paper presented at ‘Critical Issues in Qualitative Research’, July 3–7, 2001, Melbourne, Australia, and a second paper presented at ‘Strategies in Qualitative Research’, September 1–3, 2004, University of Durham, UK, (Johnston, 2001; 2004).

Notes

[1] See http://www.qsrinternational.com. Retrieved 14 October, 2004.

[2] See http://www.researchsupport.com.au. Retrieved 14 October, 2004.

[3] See endnote 1.

[4] See http://www.dur.ac.uk/strategies.conference. Retrieved 14 October, 2004.

[5] See http://caqdas.soc.surrey.ac.uk. Retrieved 14 October, 2004.

[6] See http://www.wcer.wisc.edu/tqm. Retrieved 14 October, 2004.

References

Bazeley, P. (1999). The bricoleur with a computer: Piecing together qualitative and quantitative data. Qualitative Health Research, 9(2), 279–287.

Bazeley, P. (2002). The evolution of a project involving an integrated analysis of structured qualitative and quantitative data: From N3 to NVivo. International Journal of Social Research Methodology, 5(3), 229–243.

Bazeley, P. (2003a). Computerized data analysis for mixed methods research. In A. Tashakkori & C. Teddlie (Eds.), Handbook of mixed methods in social and behavioral research (pp. 385–422). London: Sage.

Bazeley, P. (2003b). Teaching mixed methods. Qualitative Research Journal, 3 (Special issue), 117–126. Retrieved on 14 October, 2004, from http://www.latrobe.edu.au/aqr/journal/special_ AQR2003.pdf

Bazeley, P. (2004, September). Quantifying qualitative data: The construction and interpretation of codes. Paper presented at Strategies for Qualitative Research Using QSR Software, Durham, UK. Bazeley, P., & Richards, L. (2000). The NVivo qualitative project book. London: Sage.

Bell, R. (2004, July). Quantitative tools for qualitative data. Paper presented at ESRC Research Methods Festival, Oxford.

Bringer, J. D. (2002). Sexual exploitation: Swimming coaches’ perceptions and the development of role conflict and role ambiguity. Doctoral dissertation, University of Gloucestershire.

Bringer, J. D., Johnston, L. H., & Brackenridge, C. H. (2004). Maximising transparency in a doctoral thesis: The complexities of writing about the use of NVivo within a grounded theory study. Qualitative Research, 4(2), 247–265.

Bringer, J. D., Johnston, L. H., & Brackenridge, C. H. (2006). Using Computer-Assisted Qualatative

      Data Analysis Software to Develop a Grounded Theory Project, Field Methods, 18(3), 245–266. Bryman, A. (2004, August). Integrating quantitative and qualitative research: How is it done? Paper

presented at the 6th International Conference on Logic and Methodology, Amsterdam.

390 L. Johnston

Carvajal, D. (2002). The artisan’s tools: Critical issues when teaching and learning CAQDAS. Forum: Qualitative Social Research, 3(2). Retrieved from http://www.qualitative-research.net/fqs-texte/2–02/2–02carvajal-e.htm

Coupland, C., & Johnston, L. H. (2004, September). Using QSR NVivo in phenomenological research. Paper presented at Strategies in Qualitative Research, Durham, UK.

Davidson, J. (2004, September). Grading NVivo: Making the shift from training to teaching with software for qualitative data analysis. Paper presented at Strategies in Qualitative Research, Durham, UK.

Delamont, S. Aitkinson, P., & Parry, O. (2004). Supervising the doctorate: A guide to success. Maidenhead: McGraw Hill Education.

di Gregorio, S. (2000, September). Using NVivo for your literature review. Paper presented at Strategies in Qualitative Research: Issues and Results from Analysis Using QSR NVivo and NUD*IST, London.

di Gregorio, S. (2003a, May). Analysis as cycling: Shifting between coding and memoing in using qualitative analysis software. Paper presented at Strategies in Qualitative Research: Methodological Issues and Practices Using QSR NVivo and NUD*IST, London.

di Gregorio, S. (2003b). Teaching grounded theory with QSR NVivo. Qualitative Research Journal, 3(Special issue), 79–95. Retrieved on 14 October, 2004 from http://www.latrobe.edu.au/aqr/ journal/special_AQR2003.pdf

Economic and Social Research Council (2001). Post graduate training guidelines (3rd ed.). Swindon: Economic and Social Research Council.

Fielding, N. G. (2002). Automating the ineffable: Qualitative software and the meaning of qualitative research. In T. May (Ed.), Qualitative research in action (pp. 161–178). London: Sage.

Fielding, N. G., & Lee, R. M. (1998). Computer analysis and qualitative research. London: Sage. Fielding, N. G., & Lee, R. M. (2002). New patterns in the adoption and use of qualitative software. Field Methods, 14(2), 197–216.

Gibbs, G. R., Friese, S., & Mangabeira, W. C. (2002). The use of new technology in qualitative research. Forum: Qualitative Social Research, 3(2). Retrieved on 14 October, 2004 from http:// www.qualitative-research.net/fqs-texte/2–02/2–02hrsg-e.htm

Gilbert, L. S. (1999). Reflections of qualitative researchers on the uses of qualitative data analysis soft

      ware: An activity theory perspective. Doctoral dissertation, University of Georgia, Athens, GA. Gilbert, L. S. (2002). Going the distance: ‘Closeness’ in qualitative data analysis software. Interna

tional Journal of Social Research Methodology, 5(3), 215–228.

Glaser, B. (2003). The grounded theory perspective II: Descriptions of remodelling of grounded theory methodology. Mill Valley, CA: Sociology Press.

Jackson, K. (2003). Blending technology and methodology: A shift towards creative instruction of qualitative methods with NVivo. Qualitative Research Journal, 3(Special issue), 96–110. Retrieved on 14 October, 2004 from http://www.latrobe.edu.au/aqr/journal/special_ AQR2003.pdf

Jevon, S. M., & Johnston, L. H. (2001, September). Psychological impact of injury in elite athletes: An exploration of the knowledge of the governing body chartered physiotherapist. Paper presented at British Association of Sport and Exercise Sciences, Newport, UK.

Jevon, S. M., & Johnston, L. H. (2003). The perceived knowledge and attitudes of governing body chartered physiotherapists towards the psychological aspects of rehabilitation. Physical Therapy in Sport, 4(2), 74–81.

Johnston, L. H. (2001, July). Reflections on teaching qualitative software in the UK: Methodological vacuum and software skills? Paper presented at Critical Issues in Qualitative Research, Melbourne.

Johnston, L. H. (2004, September). Technical and methodological learning curves: Reflections on the

      use of QSR NVivo in doctoral research. Strategies in Qualitative Research, Durham, UK. Johnston, L. H., & Carroll, D. (1998a). The provision of social support to injured athletes: A qualita

tive analysis. Journal of Sport Rehabilitation, 7, 267–284.

International Journal of Social Research Methodology 391

Johnston, L. H., & Carroll, D. (1998b). The context of emotional responses to athletic injury: A qualitative analysis. Journal of Sport Rehabilitation, 7, 206–220.

Johnston, L. H., Corban, R. M., & Clarke, P. (1999). Multi-method approaches to the investigation of adherence issues within sport and exercise: Qualitative and quantitative techniques. In S. J. Bull (Ed.), Adherence issues in exercise and sport (pp. 263–288). Chichester: John Wiley.

Kaczynski, D. (2003). Curriculum development strategies using qualitative data analysis strategies. Qualitative Research Journal, 3(Special issue), 111–116. Retrieved on 14 October, 2004 from http://www.latrobe.edu.au/aqr/journal/special_AQR2003.pdf

Marshall, H. (2002). What do we do when we code data? Qualitative Research Journal, 2(1), 56–70.

      Retrieved on 14 October, 2004 from http://www.latrobe.edu.au/aqr/journal/1AQR2002.pdf Miles, M. B., & Huberman, A. M. (1994). Qualitative data analysis: An expanded sourcebook (2nd

ed.). London: Sage.

Morse, J. M., & Richards, L. (2002). Readme first: For a users guide to qualitative methods. London: Sage.

Richards, L. (1998). Closeness to data: The changing goals of qualitative data handling. Qualitative Health Research, 8, 319–328.

Richards, L. (1999a). Data alive! The thinking behind NVivo. Qualitative Health Research, 9(3), 412–428.

Richards, L. (1999b). Using NVivo in qualitative research. London: Sage.

Richards, L. (2000, September). Pattern analysis and why it isn’t grounded theory. Paper presented at Strategies in Qualitative Research: Issues and Results from Analysis Using QSR NVivo and NUD*IST, London, UK.

Richards, L. (2002). Qualitative computing: A methods revolution? International Journal of Social Research Methodology, 5(3), 263–276.

Richards, L. (2004, September). Validity and reliability? Yes! Doing it in software. Paper presented at Strategies in Qualitative Research, Durham, UK.

Richards, L. (2005). Handling qualitative data: A practical guide. London: Sage.

Richards, T. (2004, September). Unleash the power within! What node hierarchies are really all about, why they are at the heart of powerful research techniques, and where they can take us next? Paper presented at Strategies in Qualitative Research, Durham, UK.

Seale, C. F. (2002). Computer-assisted analysis of qualitative interview data. In J. F. Gubrium & J. A. Holstein (Eds.), Handbook of interview research: Context and method (pp. 651–670). London: Sage.

Spencer, L., Ritchie, J., Lewis, J., & Dillon, L. (2004). Quality in qualitative evaluation: A framework for assessing research evidence (2nd rev. ed.). London: Cabinet Office.

Tashakkori, A. & Teddlie, C. (Eds.) (2003). Handbook of mixed methods for the social and behavioural sciences. London: Sage.

Thompson, R. (2002, May). Reporting the results of computer-assisted analysis of qualitative research data. Forum: Qualitative Social Research, 3(2). Retrieved on 14 October, 2004 from http://www.qualitative-research.net/fqs-texte/2-02/2-02thompson-e.htm

Weitzman, E. (2003). Software and qualitative research. In N. K. Denzin & Y. S. Lincoln (Eds.), Collecting and interpreting qualitative materials (2nd ed., pp. 310–339). London: Sage.

Weitzman, E., & Miles, M. (1995). Computer programmes for qualitative data analysis: An overview. London: Sage.

Welsh, E. (2002, May). Dealing with data: Using NVivo in the qualitative data analysis process. Forum: Qualitative Social Research, 3(2). Retrieved on 14 October, 2004 from http:// www.qualitative-research.net/fqs-texte/2–02/2–02welsh-e.htm

Willig, C. (2001). Introducing qualitative research in psychology. Buckingham: Open University Press.

Copyright of International Journal of Social Research Methodology is the property of Routledge and its content may not be copied or emailed to multiple sites or posted to a listsery without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.