﻿ CONVERGE= select convergence criteria

CONVERGE= select convergence criteria = Either

This selects which of LCONV= and RCONV= set the convergence criterion. See convergence considerations.

 CONVERGE=L LCONV= for "Logit change size" controls convergence. Iteration stops when the biggest logit change is less or equal to LCONV=, or when the biggest logit change size increases (divergence). CONVERGE=R RCONV= for "Residual size" controls convergence. Iteration stops when the biggest residual score is less or equal to RCONV=, or when the biggest residual size increases (divergence). CONVERGE=E Either LCONV= for "Logit change size" or RCONV= for "Residual size" controls convergence. Iteration stops when the biggest logit change is less or equal to LCONV=, or when the biggest residual score is less or equal to RCONV=, or when both the biggest logit change size increases and the biggest residual size increases (divergence). CONVERGE=B Both LCONV= for "Logit change size" and RCONV= for "Residual size" controls convergence. Iteration stops when both the biggest logit change is less or equal to LCONV= and the biggest residual score is less or equal to RCONV=, or when both the biggest logit change size increases and the biggest residual size increases (divergence). CONVERGE=F Force both LCONV= for "Logit change size" and RCONV= for "Residual size" to control convergence. Iteration stops when both the biggest logit change is less or equal to LCONV= and the biggest residual score is less or equal to RCONV=.

Example 1: We want to be take a conservative position about convergence, requiring both small logit changes and small residual sizes when iteration ceases.

CONVERGE=Both

Example 2: We need very high precision, then specify:

CONVERGE=BOTH ; both score-residual and logit-change criteria

RCONV=.001 ; at most, one tenth of the smallest score residual needed.

LCONV=.00001  ; at most, one tenth of the highest precision to be reported.

These values are much, much smaller than the natural precision of the data, which is .5 raw score points, or the logit precision (S.E.) of the ability measures.

Example 3: We want to set the convergence criteria to match BIGSTEPS version 2.59

CONVERGE=B ; the criteria were LCONV= and RCONV=

RCONV= 0.5 ; the BIGSTEPS standards or whatever value you used

LCONV= .01

Example 4: We want to set the convergence criteria to match Winsteps version 3.20

CONVERGE=E ; the criterion was LCONV or RCONV

RCONV= 0.5 ; the 3.20 standards or whatever value you used

LCONV= .01

Example 5: We want the convergence criteria to match Winsteps version 2.85

CONVERGE= F ; force both LCONV and RCONV to be met

RCONV= 0.5 ; the 2.85 standards or whatever value you used

LCONV= .01

You may also want:

WHEXACT=NO ; centralized Wilson-Hilferty was the default

Example 6: Question: With anchored analyses, iterations never stop!

|----------------------------------------------------------------------------|

|    JMLE     MAX SCORE   MAX LOGIT    LEAST CONVERGED     CATEGORY    STEP  |

| ITERATION   RESIDUAL*    CHANGE    EXID   BYCASE   CAT   RESIDUAL   CHANGE |

|----------------------------------------------------------------------------|

|       1      -239.04       .5562    1993    392*      6      85.70   -.5960|

|       2      -105.65      -.1513    1993    392*      4     -28.92    .2745|

.....

|      18        -5.35      -.0027    2228    352*      3       2.35    .0146|

|      19        -5.16       .0029    2228    352*      3       2.31    .0106|

|      20        -5.05       .0025    2228    352*      3       2.28    .0055|

|      21        -5.00       .0010    2228    352*      3       2.26    .0075|

|      22        -4.99      -.0008    2228    352*      3       2.25    .0025|

.....

|     170        -5.00      -.0011    1377    352*      3       1.96    .0109|

|     171        -5.00       .0018     187    352*      3       1.96    .0019|

.....

The standard convergence criteria in Winsteps are preset for "free" analyses. With anchored analyses, convergence is effectively reached when the logit estimates stop changing in a substantively meaningful way. This has effectively happened by iteration 20. Note that the logit changes are less than .01 logits - i.e., even the biggest change would make no difference to the printed output (which is usually reported to 2 decimal places)

To have the current Winsteps do this automatically, set

CONVERGE=L

LCONV=.005   ; set to stop at iteration 22 - to be on the safe side.

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

 Forum Rasch Measurement Forum to discuss any Rasch-related topic

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 3rd. Ed., Bond & Fox Best Test Design, Wright & Stone
Rating Scale Analysis, Wright & Masters Introduction to Rasch Measurement, E. Smith & R. Smith Introduction to Many-Facet Rasch Measurement, Thomas Eckes Invariant Measurement with Raters and Rating Scales: Rasch Models for Rater-Mediated Assessments, George Engelhard, Jr. & Stefanie Wind Statistical Analyses for Language Testers, Rita Green
Rasch Models: Foundations, Recent Developments, and Applications, Fischer & Molenaar Journal of Applied Measurement Rasch models for measurement, David Andrich Constructing Measures, Mark Wilson Rasch Analysis in the Human Sciences, Boone, Stave, Yale
in Spanish: Análisis de Rasch para todos, Agustín Tristán Mediciones, Posicionamientos y Diagnósticos Competitivos, Juan Ramón Oreja Rodríguez
Winsteps Tutorials Facets Tutorials Rasch Discussion Groups

Coming Rasch-related Events
Jan. 5 - Feb. 2, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Jan. 10-16, 2018, Wed.-Tues. In-person workshop: Advanced Course in Rasch Measurement Theory and the application of RUMM2030, Perth, Australia (D. Andrich), Announcement
Jan. 17-19, 2018, Wed.-Fri. Rasch Conference: Seventh International Conference on Probabilistic Models for Measurement, Matilda Bay Club, Perth, Australia, Website
Jan. 22-24, 2018, Mon-Wed. In-person workshop: Rasch Measurement for Everybody en español (A. Tristan, Winsteps), San Luis Potosi, Mexico. www.ieia.com.mx
April 10-12, 2018, Tues.-Thurs. Rasch Conference: IOMW, New York, NY, www.iomw.org
April 13-17, 2018, Fri.-Tues. AERA, New York, NY, www.aera.net
May 22 - 24, 2018, Tues.-Thur. EALTA 2018 pre-conference workshop (Introduction to Rasch measurement using WINSTEPS and FACETS, Thomas Eckes & Frank Weiss-Motz), https://ealta2018.testdaf.de
May 25 - June 22, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 27 - 29, 2018, Wed.-Fri. Measurement at the Crossroads: History, philosophy and sociology of measurement, Paris, France., https://measurement2018.sciencesconf.org
June 29 - July 27, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com
July 25 - July 27, 2018, Wed.-Fri. Pacific-Rim Objective Measurement Symposium (PROMS), (Preconference workshops July 23-24, 2018) Fudan University, Shanghai, China "Applying Rasch Measurement in Language Assessment and across the Human Sciences" www.promsociety.org
Aug. 10 - Sept. 7, 2018, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
Sept. 3 - 6, 2018, Mon.-Thurs. IMEKO World Congress, Belfast, Northern Ireland www.imeko2018.org
Oct. 12 - Nov. 9, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com

Our current URL is www.winsteps.com