A decline in student performance on the Scholastic Aptitude Test, the Achievement Tests, the American College Test, and the Preliminary Scholastic Aptitude Test has been observed nationally since the mid 1960's and evidence indicates that very similar trends have occurred in Massachusetts. Score declines have occurred in public, private, and parochial schools and in urban, suburban, and rural communities. Various explanations for the score decline have been proposed, some have been confirmed, some disconfirmed, and some remain doubtful. The equated score scale appears to remain stable, but there have been some changes in test content. Changes in the characteristics of the applicant group since 1971 appear not to have had any significant effect. School related factors, such as student motivation and curricular offerings, may have had some effect. The effects of changes in the social and cultural context within which the educational system operates are difficult to evaluate. Although changes in student motivation, course enrollment, and school curriculum are speculated to be major contributors to the decline, it cannot be attributed to one set of factors. Further research is recommended. (CTM)