Response process validity evidence provides a window into a respondent's cognitive processing. The purpose of this study is to describe a new data collection tool called a whole-class think aloud (WCTA). This work is performed as part of test development for a series of problem-solving measures to be used in elementary and middle grades. Data from…

Numerous diagnostic studies have been conducted on large-scale assessments to illustrate the students' mastery profile in the areas of math and reading; however, for science a limited number of investigations are reported. This study investigated Iranian eighth graders' competency mastery of science and examined the utility of the General…