CODES= valid data codes = 01

Top Up Down  A A

Says what characters to recognize as valid codes in your data file. If XWIDE=1 (the standard), use one column/character per legitimate code. If XWIDE=2, use two columns/characters per valid code. Characters in your data not included in CODES= are given the MISSCORE= value. The maximum number of codes in CODES= is 255.

 

Initially, Winsteps assumes that all items share the same response structure.

If there are 2 response codes in CODES=, then this is the Rasch dichotomous model

If there are 3 or more response codes in CODES=, then this the Andrich rating-scale model.

To override those,

If ISGROUPS=0, then this is the Masters partial-credit model. Each item is modeled to have its own rating-scale structure.

If ISGROUPS = AABBACDDCAADEEA, then the items are grouped to share rating scales.

The "A" group are items 1,2,5, 10,11,15 - they share the same rating scale.

The "B" group are items 3,4 - they share the same rating scale.

The "C" group ....

 

Example 1: A test has four response choices. These are "1", "2", "3", and "4". All other codes in the data file are to be treated as "item not administered". Each response uses 1 column in your data file. Data look like: 134212342132.3212343221

   XWIDE=1  one character wide (the standard)

   CODES=1234 four valid 1-character response codes

 

Example 2: There are four response choices. Each response takes up 2 columns in your data file and has leading 0's, so the codes are "01", "02", "03" and "04". Data look like: 0302040103020104040301

   XWIDE=2  two characters wide

   CODES=01020304 four valid 2-character response codes

 

Example 3: There are four response choices entered on the file with leading blanks, so that codes are " 1", " 2", " 3", and " 4". Data look like: 3 2 4 2 1 3 2

XWIDE=2  two characters wide

CODES=" 1 2 3 4" " required: blanks in 2-character responses

 

Note: when XWIDE=2 or more, both CODES= and the data value are left-aligned before matching, so both " 1" and "1 " in CODES= match both " 1" and "1 "in your data file.

 

Example 4: Your data is a mixture of both leading blanks and leading 0's in the code field, e.g. "01", " 1", " 2", "02" etc. The numerical value of a response is calculated, where possible, so that both "01" and " 1" are analyzed as 1.

Data look like:  02 1 20102 1 2 01

XWIDE=2  two characters wide

CODES=" 1 2 3 401020304" two characters per response

 

Example 5: Your valid data are 1,2,3,4,5 and your missing data codes are 7,8,9 which you want reported separately on the distractor tables.

 CODES = 12345789

 NEWSCORE = 12345XXX ; missing values scored with non-numeric values

 

Example 6: The valid responses to an attitude survey are "a", "b", "c" and "d". These responses are to be recoded "1", "2", "3" and "4". Data look like: adbdabcd

 CODES   =abcd four valid response codes

 NEWSCORE=1234 new values for codes

 RESCORE=2  rescore all items

 

Typically, "abcd" data implies a multiple choice test. Then KEY1= is used to specify the correct response. But, in this example, "abcd" always mean "1234", so that the RESCORE= and NEWSCORE= options are easier to use.

 

Example 7: Five items of 1-character width, "abcd", then ten items of 2-character width "AA", "BB", "CC", "DD". These are preceded by person-id of 30 characters. Data look like:

George Washington Carver III  dabcdBBAACCAADDBBCCDDBBAA

 FORMAT=(30A1,5A1,10A2) Name 30 characters, 5 1-chars, 10 2-chars

 XWIDE =2   all converted to 2 columns

 CODES ="a b c d AABBCCDD" "a" becomes "a "

 NEWSCORE="1 2 3 4 1 2 3 4 " response values

 RESCORE=2   rescore all items

 NAME1=1   name starts column 1 of reformatted record

 ITEM1=31   items start in column 31

 NI=15   15 items, all XWIDE=2

 

Example 8: Items are to rescored according to Type A and Type B. Other items to keep original scoring.

 IREFER = AAAAAAAABBBBBBBBCCCCCCC ; 3 item types

 CODES   = 1234 Original codes in the data file

 IVALUEA = 1223 Recode Type A items

 IVALUEB = 1123 Recode Type B items

 IVALUEC = 1234 Recode Type * item. Can be omitted

 

Example 9: The valid responses are percentages in the range 00 to 99.

 XWIDE = 2  two columns each percent

 ; for data with leading zeroes,

 CODES = 0001020304050607080910111213141516171819+

  +2021222324252627282930313233343536373839+

  +4041424344454647484950515253545556575859+

  +6061626364656667686970717273747576777879+

  +8081828384858687888990919293949596979899

or, for data with leading blanks,

 CODES =" 0 1 2 3 4 5 6 7 8 910111213141516171819+

  +2021222324252627282930313233343536373839+

  +4041424344454647484950515253545556575859+

  +6061626364656667686970717273747576777879+

  +8081828384858687888990919293949596979899"

 

Example 10: Codes are in the range 0-254 (the maximum possible).

XWIDE=3 ; 3 characters per response: data with leading blanks

CODES="  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23+

      + 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47+

      + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71+

      + 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95+

      + 96 97 98 99100101102103104105106107108109110111112113114115116117118119+

      +120121122123124125126127128129130131132133134135136137138139140141142143+

      +144145146147148149150151152153154155156157158159160161162163164165166167+

      +168169170171172173174175176177178179180181182183184185186187188189190191+

      +192193194195196197198199200201202203204205206207208209210211212213214215+

      +216217218219220221222223224225226227228229230231232233234235236237238239+

      +240241242243244245246247248249250251252253254"

 

Example 11: The data include negative values, -10, -9, through to positive codes 9, 10. Winsteps can only analyze data that are positive integers, so the data would need to be rescored:

XWIDE=3 ; each observation is 3 characters wide in the data file

; the next line is so that I can be sure that each code is 3 characters wide

;         123123123123123123123123123123123123123123123123123123123123123

CODES   ="-10-9 -8 -7 -6 -5 -4 -3 -2 -1 0  1  2  3  4  5  6  7  8  9  10 "

NEWSCORE="0  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17 18 19 20 "


Help for Winsteps Rasch Measurement Software: www.winsteps.com. Author: John Michael Linacre

Facets Rasch measurement software $149.
Winsteps Rasch measurement software $149.

State-of-the-art : single-user and site licenses : free student/evaluation versions : download immediately : instructional PDFs : user forum : assistance by email : bugs fixed fast : free update eligibility : backwards compatible : money back if not satisfied
 
Rasch, Winsteps, Facets online Tutorials

Forum Rasch Measurement Forum to discuss any Rasch-related topic

To receive the monthly News Email about Winsteps and Facets,
enter your email address here:

I want to Subscribe: & click below
I want to Unsubscribe: & click below

Please set your SPAM filter to accept emails from Winsteps.com
www.winsteps.com welcomes your comments:

Your email address (if you want us to reply):

 

Rasch Publications
Rasch Measurement Transactions (free, online) Rasch Measurement research papers (free, online) Probabilistic Models for Some Intelligence and Attainment Tests, Georg Rasch
Applying the Rasch Model 2nd. Ed., Bond & Fox (Winsteps) Best Test Design, Wright & Stone Rating Scale Analysis, Wright & Masters
Rasch Analysis in the Human Sciences, W. Boone, J. Staver, M. Yale Introduction to Many-Facet Rasch Measurement, Thomas Eckes (Facets) Invariant Measurement: Using Rasch Models in the Social, Behavioral, and Health Sciences, George Engelhard, Jr. (Facets)
Statistical Analyses for Language Testers, Rita Green (Winsteps, Facets) Rasch Models: Foundations, Recent Developments, and Applications, Fischer & Molenaar Journal of Applied Measurement
Winsteps Tutorials Facets Tutorials Rasch Discussion Groups

Coming Rasch-related Events
Oct. 31 - Nov. 28, 2014, Fri.-Fri. On-line workshop: Rasch Applications, Part 2: Clinical Assessment, Survey Research, and Educational Measurement (W. Fisher), www.statistics.com
Nov. 14, 2014, Fri. In-person workshop: IX Workshop on Rasch Models in Business Administration, Tenerife, Canary Islands, Spain, www.institutos.ull.es/viewcontent/institutos/iude/46416/es
Nov. 30, 2014, Sun. Submission deadline: 6th Rasch Conference: Sixth International Conference on Probabilistic Models for Measurement in Education, Psychology, Social Science and Health, Cape Town, South Africa www.rasch.co.za/conference.php
Dec. 3-5, 2014, Wed.-Fri. In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
Jan. 2-30, 2015, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Jan. 12-14, 2015, Mon.-Wed. 6th Rasch Conference: Sixth International Conference on Probabilistic Models for Measurement in Education, Psychology, Social Science and Health, Cape Town, South Africa www.rasch.co.za/conference.php
March 11-13, 2015, Wed.-Fri. In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
March 20, 2015, Fri. UK Rasch User Group Meeting, London, United Kingdom, www.rasch.org.uk
March 26-27, 2015, Thur.-Fri. In-person workshop: Introduction to Rasch Measurement with Winsteps (W. Boone), Cincinnati, raschmeasurementanalysis.com
April 16-20, 2015, Thurs.-Mon. AERA Annual Meeting, Chicago IL www.aera.net
April 21-22, 2015, Tues.-Wed. IOMC 2015: International Outcomes Measurement Conference, Chicago IL www.jampress.org
May 13-15, 2015, Wed.-Fri. In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
May 18-20, 2015, Mon.-Wed. In-person workshop: Intermediate Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
May 29 - June 26, 2015, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
July 3-31, 2015, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com
Aug. 14 - Sept. 11, 2015, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
Sept. 9-11, 2015, Wed.-Fri. In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
Sept. 14-16, 2015, Mon.-Wed. In-person workshop: Intermediate Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
Sept. 17-18, 2015, Thur.-Fri. In-person workshop: Advanced Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
Oct. 16 - Nov. 13, 2015, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Sept. 4 - Oct. 16, 2015, Fri.-Fri. On-line workshop: Rasch Applications, Part 1: How to Construct a Rasch Scale (W. Fisher), www.statistics.com
Oct. 23 - Nov. 20, 2015, Fri.-Fri. On-line workshop: Rasch Applications, Part 2: Clinical Assessment, Survey Research, and Educational Measurement (W. Fisher), www.statistics.com
Dec. 2-4, 2015, Wed.-Fri. In-person workshop: Introductory Rasch (A. Tennant, RUMM), Leeds, UK, www.leeds.ac.uk/medicine/rehabmed/psychometric
Aug. 12 - Sept. 9, 2016, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
The HTML to add "Coming Rasch-related Events" to your webpage is:
<script type="text/javascript" src="http://www.rasch.org/events.txt"></script>