Raw Score-to-Measure (Scaled Score) Tables

Question: Is it good practice for me to supply a lookup table or Excel sheet to convert sum scores into the measure scores so that users get their results on an interval scale? Is there a good example to cite?

Answer: Many publishers and authors supply a "raw score to scale score" conversion chart. It is convenient for the users, and also allows different versions and revisions of the instrument to continue to generate comparable scale scores. Here is an example showing raw scores and their Rasch logit equivalents:

Hsueh I-P., Wang W.-C., Sheu C.-F., and Hsieh C.-L. (2004) Rasch Analysis of Combining Two Indices to Assess Comprehensive ADL Function in Stroke Patients. Stroke, 35(3): 721 - 726.

But it is more useful to publish a transformation of Rasch logits, not the logits themselves. Transform the logits such that all Rasch "scores" are reported as positive integers. Here is a rescaled example. You can note the exact logit transformation as a footnote to the Table if it will be meaningful to your readers.

Ohio Department of Education, Office of Assessment

Raw Score-to-Measure (Scaled Score) Tables. … Rasch Measurement Transactions, 2007, 21:1 p. 1095

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

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