﻿ USCALE= the user-scaled value of 1 logit

# USCALE= the user-scaled value of 1 logit = 1

Specifies the number of reported user-scaled units per logit. When USCALE=1 (or USCALE= is omitted) then all measures are in logits.

Table 20 gives the UMEAN= and USCALE= values for a conversion that gives the measures a range of 0-100.

Example 1: You want to user-rescale 1 logit into 45.5 units, so that differences of -100, -50, 0, +50, +100 correspond to success rates of 10%, 25%, 50%, 75%, 90%:

USCALE = 45.5

Example 2: You want to reverse the measurement directions, since the data matrix is transposed so that the 'items' are examinees and the 'persons' are test questions:

USCALE = -1

KEYn=, RESCORE=, ISGROUPS= will still apply to the columns, not the rows, of the data matrix. Centering will still be on the column measures.

Example 3: You want to approximate the "probit" measures used in many statistical procedures.

UPMEAN = 0  ; set the person sample mean to zero

USCALE = 0.59  ; probits * 1.7 = logits

Example 4: You want to report measures in "log-odds units to the base 10" (lods) instead of the standard "logits to the base e".

USCALE=0.434294482 ; the conversion between "natural" and base-10 logarithms.

For more examples, and how to compute this by hand, see User-friendly rescaling

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

## Just released in June 2017: Winsteps 4.0 with Table 45 Cumulative Plot

### New: Masterchef Australia 2017: Rasch Measurement of Cooks with Table 45

 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: Using Rasch Models in the Social, Behavioral, and Health Sciences, George Engelhard, Jr. 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
Sept. 27-29, 2017, Wed.-Fri. In-person workshop: Introductory Rasch Analysis using RUMM2030, Leeds, UK (M. Horton), Announcement
Oct. 13 - Nov. 10, 2017, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Oct. 25-27, 2017, Wed.-Fri. In-person workshop: Applying the Rasch Model hands-on introductory workshop, Melbourne, Australia (T. Bond, B&FSteps), Announcement
Dec. 6-8, 2017, Wed.-Fri. In-person workshop: Introductory Rasch Analysis using RUMM2030, Leeds, UK (M. Horton), Announcement
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
April 13-17, 2018, Fri.-Tues. AERA, New York, NY, www.aera.net
May 25 - June 22, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 29 - July 27, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com
Aug. 10 - Sept. 7, 2018, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
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