When an assessment undergoes changes to the administration or instrument, bridge studies are typically used to try to ensure comparability of scores before and after the change. Among the most common and powerful is the common population linking design, with the use of a linear transformation to link scores to the metric of the original…

Guessing behavior is an issue discussed widely with regard to multiple choice tests. Its primary effect is on number-correct scores for examinees at lower levels of proficiency. This is a systematic error or bias, which increases observed test scores. Guessing also can inflate random error variance. Correction or adjustment for guessing formulas…

Critics of standardized testing have recommended replacing standardized tests with more authentic assessment measures, such as classroom assignments, projects, or portfolios rated by a panel of raters using common rubrics. Little research has examined the consistency of scores across multiple authentic assignments or the implications of this…

The usual formulas for the reliability of differences between two test scores are based on the assumption that the error scores are uncorrelated. Formulas are presented for the general case where this assumption is unnecessary. (Author/JKS)

The author has discovered that errors in grades often occur when scores are combined for final marks. These errors are not related to the grading individual assignments. Rather, they occur when teachers at all grade levels bring individual test and assignment scores together for the students' final grades. Unfortunately, professors of mathematics…

Previous studies of test item bias have investigated how different groups of examinees perform differently on a given set of items. These studies imply that examinees should be treated in a certain way because they are of a particular sex or race rather than as individuals in their own right, but it is unrealistic and unfair to assume such an…