The purpose of this research study was to assess item response model-test data fit using residuals. First, a comparison of raw and standardized residuals for describing model-test data fit was carried out. Second, hypotheses concerning the relationship between residual sizes and several item characteristics were studied. The analyses with…

Four researchers at the Educational Testing Service describe what they consider some of the most vexing research problems they face. While these problems are not completely statistical, they all have major statistical components. Following the introduction (section 1), in section 2, "Problems with the Simultaneous Estimation of Many True…

Efficient methods of using the Statistical Package for the Social Sciences (SPSS) to analyze National Assessment of Educational Progress (NAEP) data files are discussed. One error in the NAEP SPSS file is discussed, and another error (which may be system-dependent) is mentioned. In addition, purely mathematical methods are used to address the…

This paper analyzes data from the "High School and Beyond" study on approximately 30,000 sophomores in 1,000 U.S. schools. The purpose is to explain the contradictory conclusions offered by two recent national studies on public and private schooling. The analysis examines differences between public and private school students in…