Because test scores are ordinal not cordinal attributes, the average test score often is a misleading way to summarize the scores of a group of individuals. Similarly, correlation coefficients may be misleading summary measures of association between test scores. Proper, readily interpretable, summary statistics are developed from a theory of…

Estimation techniques for generating the covariance matrix for two new tests and an existing test without the necessity of any examinee having to take two complete tests is presented. An application of these techniques to linear, observed-score, test equating is presented. (Author/JKS)

An important determinant of equating process efficiency is the correlation between the anchor test and components of each form. Use of some monotonic function of this correlation as a measure of equating efficiency is suggested. A model relating anchor test length and test reliability to this measure of efficiency is presented. (Author/DWH)

The idea that validity should be considered a property of inferences, rather than of assessments, has developed slowly over the past century. In early writings about the validity of educational assessments, validity was defined as a property of an assessment. The most common definition was that an assessment was valid to the extent that it…