Unidimensionality and local independence are two common assumptions of item response theory. The former implies that all items measure a common latent trait, while the latter implies that responses are independent, conditional on respondents' location on the latent trait. Yet, few tests are truly unidimensional. Unmodeled dimensions may result in…

The purpose of the present article is to report on a large-scale investigation of six school districts' implementation of an initiative aimed at reducing dropout rates by improving reading achievement in the middle grades. Data for the Middle School Intervention Project (MSIP) were collected in 25 middle schools across the state of Oregon. We…

In response to a request for additional analyses, in particular reporting confidence intervals around the results, we re-analyzed the data from prior studies. This supplementary report presents the results of the additional analyses addressing classification accuracy, reliability, and criterion-related validity evidence. For ease of reference, we…

In response to a request for additional analyses, in particular reporting confidence intervals around the results, we re-analyzed the data from prior studies. This supplementary report presents the results of the additional analyses addressing classification accuracy, reliability, and criterion-related validity evidence. For ease of reference, we…

This in-brief technical report documents the results from two different analytic approaches for examining the reliability of the slope for easyCBM® math measures in Grades K-8. Results varied by grade, assessment measure, and the analytic approach. Results patterns are discussed.

This in-brief technical report documents the results from two different analytic approaches for examining the reliability of the slope for easyCBM® reading measures in Grades K-8. Results varied by grade, assessment measure, and the analytic approach. Results patterns are discussed.