Needed: Test-free Scaling!

Wegener B. (1997) Needed: Test-free Scaling! Rasch Measurement Transactions 11:1 p. 543.

"Recent developments in psychophysics tacitly tend towards a new position, ... in which a definition for a sensation scale is not fixed in advance, but rather in which formal criteria are established to provide guidelines for a decision on such a definition [axioms of measurement]. Several formulations have been suggested ... All have in common their author's conviction that it would be unfortunate to have several scales of sensation depending on the number of tasks, methods, or paradigms provided. Instead, the appealing feature is the ability to merge all different scales into one scale, which will then gain the status of a valid sensation scale. [test-free scaling]

"Clearly, a primary aspect of this position is economy of explanatory concepts. In this respect it is harmonious with current views in the philosophy of science, according to which the guiding principle in scientific concept formation is richness of empirical content [large universe of possible items] and predictive power. Therefore, a theory of sensation that establishes a task-independent scale will have a 'progressive' quality in comparison with others.

"With the prospect of the development of a framework for merging scales ahead, the real problem is, of course, determining how the convergence of scales is to be accomplished, if, indeed, it can be accomplished at all [Take heart- Rasch to the rescue!]. Obviously, it will not do merely to seek sophisticated transformation schemes by which scales of different types can be related [descriptive techniques]... because interscale transformations do not tell us to which basic scales the others should be adapted [i.e., which scale usefully represents the construct]."

Bernd Wegener (1982) Introduction, In Social Attitudes and Psychophysical Measurement, B Wegener (Ed.), Hillsdale, NJ: Lawrence Erlbaum, p. 4.
Courtesy of William P. Fisher. Jr.

Needed: Test-free Scaling! Wegener B. … Rasch Measurement Transactions, 1997, 11:1 p. 543.

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