Description: Papers of Ledyard R. Tucker, professor of psychology (1960-79), including correspondence, publications, reports, manuscripts, research notes, course materials, test materials and computer INT-outs relating to Tucker's research on factor analysis, three-mode factor analysis and mental test theory; teaching of measurement psychology techniques; and professional, and administrative activities. The papers include material on the Psychometric Society (1961-73, President 1955), the American Psychological Association, Division 5, Evaluation and Measurement (1959-63, President 1962), and Psychometrika (1954-74), Editorial Board member 1945-72). Tucker was associated with the Educational Testing Service as Director of Statistical Analysis (1948-52) and Research Associate (1952-60). His factor analysis research was funded by the Office of Naval Research (1961-70).