Item purification is an iterative process that is often advocated as improving the identification of items affected by differential item functioning (DIF). With test-score-based DIF detection methods, item purification iteratively removes the items currently flagged as DIF from the test scores to get purified sets of items, unaffected by DIF. The…

This article examines the multilevel linear crossed random effects growth model for estimating teacher and school effects from repeated measurements of student achievement. Results suggest that even a small degree of unmodeled nonlinearity can result in a substantial upward bias in the magnitude of the teacher effect, which raises concerns about…

There is disagreement among researchers as to whether creativity is a unidimensional or multidimensional trait. Much of the debate centers around the most widely used measure of creativity, the Torrance Tests of Creative Thinking (TTCT). This study used data from 1,000 kindergartners (ages 5-7), 1,000 third graders (ages 7-11) and 1,000 sixth…

The present study investigated the differential predictive validity of the Initial Skills Analysis. In the fall, these reading screening tests were administered to students in Grades K to 3. In the spring, a series of reading outcomes tests were administered to these same students, and teachers provided judgments of the students' reading skills.…