Robert L. Ebel: "These observations suggest that the concept of validity itself may be weak scientifically. Most of the definitions of validity can be shown to be derived from the basic notion that validity is the degree to which a test measures what it is supposed to measure. But how does one know what a test is supposed to measure? On a superficial level, perhaps, it may be suggested by the test title - academic aptitude, mathematics achievement, or social studies background, for example - but these suggestions are by no means definitive.
"Does the criterion [i.e., definitive information outside the test] tell us what the test is supposed to measure? It might, if criteria were given to us. Usually they are not. They have to be devised, often after the test itself was constructed. Toops (1944) has said:
Possibly as much time should be spent in devising the criterion as in constructing and perfecting the test. This important part of a research seldom receives half the time or attention it requires or deserves. If the criterion is slighted the time spent on the tests is, by so much, largely wasted.
"The ease with which test developers can be induced to accept as criterion measures quantitative data [for test validation by correlation], having the slightest appearance of relevance to the trait being measured is one of the scandals of psychometry. To borrow a figure of speech from Thorndike (1922), they will use the loudness of the thunder as a criterion for their measurements of the voltage of the lightning."
Ebel R. L. (1961) Must all tests be valid? American Psychologist, 16, 640-7, reprinted in p.222-3 in W. A. Mehrens & R. L. Ebel (Eds.) Principles of Educational and Psychological Measurement. Chicago: Rand McNally. 1967.
Thorndike E.L. (1922) Measurement in education. 21st Yearbook, NSSE. Bloomington, Il: Public School Publishing Co.
Toops H. A. (1944) The criterion. Educ. Psychol. Meas., 4, 271-297.
Music is the art of measuring well.
Augustine of Hippo
Validity by Theory Ebel, R.L. Validity by Numbers vs. Rasch Measurement Transactions, 1999, 13:3 p. 713
Please help with Standard Dataset 4: Andrich Rating Scale Model
|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|
|Forum||Rasch Measurement Forum to discuss any Rasch-related topic|
Go to Top of Page
Go to index of all Rasch Measurement Transactions
AERA members: Join the Rasch Measurement SIG and receive the printed version of RMT
Some back issues of RMT are available as bound volumes
Subscribe to Journal of Applied Measurement
Go to Institute for Objective Measurement Home Page. The Rasch Measurement SIG (AERA) thanks the Institute for Objective Measurement for inviting the publication of Rasch Measurement Transactions on the Institute's website, www.rasch.org.
|Coming Rasch-related Events|
|Sept. 15-16, 2017, Fri.-Sat.||IOMC 2017: International Outcome Measurement Conference, Chicago, jampress.org/iomc2017.htm|
|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|
|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|
|The HTML to add "Coming Rasch-related Events" to your webpage is:|
The URL of this page is www.rasch.org/rmt/rmt133r.htm