It is imperative to collect validity evidence prior to interpreting and using test scores. During the process of collecting validity evidence, test developers should consider whether test scores are contaminated by sources of extraneous information. This is referred to as construct irrelevant variance, or the "degree to which test scores are…

A conceptualization of multiple-choice exams in terms of signal detection theory (SDT) leads to simple measures of item difficulty and item discrimination that are closely related to, but also distinct from, those used in classical item analysis (CIA). The theory defines a "true split," depending on whether or not examinees know an item,…

In the arena of educational testing, accessibility refers to the degree to which students are given the opportunity to participate in and engage a test. Accessibility theory is a model for examining the interactions between the test-taker and the test itself and defining how they may decrease some students' access to the test event, ultimately…

Studied effects of students' use of calculators with 2 experimental forms of a university mathematics test taken by 765 and 725 college students, respectively. Calculator effects are not found for overall scores but are seen for some individual items. Analysis at the item level makes the actual impact apparent. (SLD)

Data available from the Fall and Spring administration of the Stanford Achievement Test: Intermediate I: Form X and the Otis-Lennon Mental Ability Test for all Title I pupils in the State of New Hampshire plus a random sample for the entire state, made possible the item-by-item comparison of Fall and Spring performance on the same groups of…