We must explain why science - our surest example of sound
knowledge - progresses as it does, and we first must find out how,
in fact, it does progress.
Thomas Kuhn, 1970a, p.20
The adequacy or effectiveness of individual theories is a
function of how many significant empirical problems they solve, and
how many important anomalies and conceptual problems they
Larry Laudan, 1977, p.119
How should "progress" be defined and evaluated for measurement theory? Progress can be defined in different ways. Bury (1932) provides a historical analysis of how the idea of progress has changed over time. This change continues. For some philosophers of science, progress is defined in terms of the number of empirical problems successfully solved (Kuhn, 1970b). Empirical problems are substantive questions about objects which constitute the domain of any given science (Laudan, p.15).
Other philosophers argue that the overall problem-solving effectiveness of a theory is determined by assessing the number and importance of empirical problems which the theory solves and deducting therefrom the number and importance of the anomalies and conceptual problems which the theory generates (Laudan, p.68). Conceptual problems are characteristics of theories with no existence independent of the theories themselves. Conceptual problems depend on the well-foundedness of the conceptual structures (e.g., theories) which have been devised to answer the first-order [empirical] questions (Laudan, p.48). Since conceptual problems could devalue even the most effective solution to an empirical problem, surely our definition of progress must encompass both components.
What are the major empirical and conceptual measurement problems in the social sciences? Are some problems more important than others? What are the criteria for defining acceptable solutions to crucial problems? Can objective criteria be developed for comparing the problem-solving effectiveness of different measurement theories?
In item response theory, IRT, the responses of individuals to test items define the objects of study. Empirical questions can be raised such as "How well does the model fit the data?" or "How well do data fit the model?" If empirical criteria alone defined problem-solving effectiveness, then the better theory would provide the better model-data fit. When, however, conceptual problems are also considered, theory evaluations must include the illogical consequences of some measurement theories, such as the crossed item characteristic curves that follow from Birnbaum's model, and the attenuation paradox of "true score" theory.
Once the crucial empirical and conceptual problems are defined, progress can be examined by comparing the problem-solving effectiveness of competing theories. The effectiveness of a single measurement theory can also be examined over time by evaluating how well it deals with new problems that did not exist when it was formulated. Computerized adaptive testing (CAT) systems did not exist when Spearman laid the groundwork for "true score" theory, nor when Rasch developed his measurement theory. We now see that "true score" theory cannot provide a useful solution for CAT measurement problems. On the other hand, practical CAT systems have been developed using the Rasch model.
Professor George Engelhard, Jr.
Division of Educational Studies
Bury J.B. 1932. The idea of progress: An inquiry into its growth and origin. New York: Dover.
Kuhn T. 1970a. Logic of discovery or psychology of research? In Lakatos and Musgrave, Criticism and the growth of knowledge. London: Cambridge University Press.
Kuhn T. 1970b. The structure of scientific revolutions. 2nd Edition, enlarged. Chicago: The University of Chicago Press.
Laudan L. 1977. Progress and its problems: Towards a theory of scientific growth. Berkeley, CA: University of California Press.
Progress in Measurement Theory. G. Engelhard, Jr. Rasch Measurement Transactions, 1992, 6:1, 204
|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|
|March 21, 2019, Thur.||13th annual meeting of the UK Rasch user group, Cambridge, UK, http://www.cambridgeassessment.org.uk/events/uk-rasch-user-group-2019|
|April 4 - 8, 2019, Thur.-Mon.||NCME annual meeting, Toronto, Canada,https://ncme.connectedcommunity.org/meetings/annual|
|April 5 - 9, 2019, Fri.-Tue.||AERA annual meeting, Toronto, Canada,www.aera.net/Events-Meetings/Annual-Meeting|
|April 12, 2019, Fri.||On-line course: Understanding Rasch Measurement Theory - Master's Level (G. Masters), https://www.acer.org/au/professional-learning/postgraduate/rasch|
|July 2-5, 2019, Tue.-Fri.||2019 International Measurement Confederation (IMEKO) Joint Symposium, St. Petersburg, Russia,https://imeko19-spb.org|
|July 11-12 & 15-19, 2019, Thu.-Fri.||A Course in Rasch Measurement Theory (D.Andrich), University of Western Australia, Perth, Australia, flyer - http://www.education.uwa.edu.au/ppl/courses|
|Aug 5 - 10, 2019, Mon.-Sat.||6th International Summer School "Applied Psychometrics in Psychology and Education", Institute of Education at HSE University Moscow, Russia.https://ioe.hse.ru/en/announcements/248134963.html|
|Aug. 9 - Sept. 6, 2019, Fri.-Fri.||On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com|
|Aug. 14 - 16, 2019. Wed.-Fri.||An Introduction to Rasch Measurement: Theory and Applications (workshop led by Richard M. Smith) https://www.hkr.se/pmhealth2019rs|
|August 25-30, 2019, Sun.-Fri.||Pacific Rim Objective Measurement Society (PROMS) 2019, Surabaya, Indonesia https://proms.promsociety.org/2019/|
|Oct. 11 - Nov. 8, 2019, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com|
|Nov. 3 - Nov. 4, 2019, Sun.-Mon.||International Outcome Measurement Conference, Chicago, IL,http://jampress.org/iomc2019.htm|
|Jan. 24 - Feb. 21, 2020, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com|
|May 22 - June 19, 2020, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com|
|June 26 - July 24, 2020, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com|
|Aug. 7 - Sept. 4, 2020, Fri.-Fri.||On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com|
|Oct. 9 - Nov. 6, 2020, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com|
|June 25 - July 23, 2021, Fri.-Fri.||On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com|
The URL of this page is www.rasch.org/rmt/rmt61f.htm