An error in an essential equation within the article by Williams and Zimmerman is corrected, and the algebraic inequalities are translated into questions a researcher can ask about simple or residualized difference scores. Williams and Zimmerman acknowledge the error and note that main conclusions are not affected. (SLD)

Findings cast doubt on the overall utility of the CMAS with retarded children. (MB)

Behavioral Expectation Scales (BES) were compared to summated and trait-oriented scales as measures of teaching performance. The psychometric evidence suggests that the summated format is slightly superior. In terms of practicality (ease of use, defensibility, and accuracy), the summated scale is definitely superior. (Author/BW)

The reliability of simple difference scores is greater than, less than, or equal to that of residualized difference scores, depending on whether the correlation between pretest and posttest scores is greater than, less than, or equal to the ratio of the standard deviations of pretest and posttest scores. (Author)

Three types of test were compared: a completion test, a matching test, and a multiple-choice test. The completion test was more reliable than the matching test, and the matching test was more reliable than the multiple-choice test. (Author/BW)

The indices of item difficulty and discrimination, the coefficients of effective length, and the average item information for both single- and multiple-answer items using six different scoring formulas were computed and compared. These formulas vary in terms of the assignment of partial credit and the correction for guessing. (Author/BW)

Classification studies are important for practitioners who need to identify individuals for specialized treatment or intervention. When interventions are irreversible or misclassifications are costly, information about the proficiency of different classification procedures becomes invaluable. This study furnishes information about the relative…