Validity is broadly defined as how well something measures what it's supposed to measure. The reliability and validity of scores from assessments are two concepts that are closely knit together and feed into each other.

E. L. Thorndike contributed significantly to the field of educational and psychological testing as well as more broadly to psychological studies in education. This article follows in his testing legacy. I address the escalating demand, across societal sectors, to measure individual and group competencies. In formulating an approach to measuring…

Objective: Crits-Christoph, Connolly Gibbons, Hamilton, Ring-Kurtz, and Gallop (2011) used generalizability theory to critique the measurement of the therapeutic alliance in psychotherapy research, showing that the dependability of alliance scores may be quite low, which in turn can lead to attenuated alliance-outcome correlation estimates. Method…

We discuss generalizability (G) theory and the fair and valid assessment of linguistic minorities, especially emergent bilinguals. G theory allows examination of the relationship between score variation and language variation (e.g., variation of proficiency across languages, language modes, and social contexts). Studies examining score variation…

In recent years, interest has grown in using classroom observation as a means to several ends, including teacher development, teacher evaluation, and impact evaluation of classroom-based interventions. Although education practitioners and researchers have developed numerous observational instruments for these purposes, many developers fail to…

Presents a model-based approach to rater reliability for essays read by multiple raters. The approach is motivated by generalizability theory, and variation of rater severity and rater inconsistency is considered in the presence of between-examinee variations. Illustrates methods with data from standardized educational tests. (Author/SLD)

The Interrater/Test Reliability System (ITRS) is described. The ITRS is a comprehensive computer tool used to address questions of interrater reliability that computes several different indices of interrater reliability and the generalizability coefficient over raters and topics. The system is available in IBM compatible or Macintosh format. (SLD)