This paper examined test scores and information about test takers collected from the Graduate Record Examination (GRE) national test administration files, GRE validity study data provided by institutional users, and survey questionnaires sent to test repeaters. Data were collected from 200,000 men and women who took the GRE General Test in June 1980-81 and from almost 900 persons who repeated the GRE General Test in June 1980. In both studies data were examined separately for four age groups of test takers--age 22 or less, 23-29, 30-39, and 40 or more--and two groups returning to graduate study after the bachelor's degree--those 9 to 15 years beyond the baccalaureate, and those 16 or more years beyond the undergraduate degree. Research concluded that early- and middle-aged adults taking the GRE General Test earn verbal ability scores similar to scores of younger applicants interested in the same fields of graduate study, while average quantitative scores are lower for test takers age 30 or older than for those age 20-22 in almost every field. Both scores predict first-year graduate school grades with approximately equal accuracy for all age groups. Among test repeaters, test preparation seemed more closely related to score changes than any other factor investigated. (PN)