Since Cronbach's (1951) elaboration of a from its introduction by Guttman (1945), this coefficient has become ubiquitous in characterizing assessment instruments in education, psychology, and other social sciences. Also ubiquitous are caveats on the calculation and interpretation of this coefficient. This article summarizes a recent contribution…

The authors describe the significant contributions of Robert Ebel to educational measurement theory and its applications. A biographical sketch details Ebel's roots and professional resume. His influence on classroom assessment views and procedures are explored. Classic publications associated with validity, reliability, and score interpretation…

Tracing the development of the Otis test series, the author argues that there will be a continuing demand for group-administered general mental ability tests in education. He foresees a need for better ways of relating ability test scores with skills and achievements to make them more educationally useful. (Author/JAZ)