The data obtained from the National Longitudinal Study of the High School Class of 1972 was used to yield estimates of the total number of instructional hours in each of the academic areas over a 3 year period. Rates of exposure to industrial arts and commercial courses exhibited large sex differences and small racial differences. Both white and female advantages in exposure were due to differences in rates at which groups initiated course taking. Program differences in academic instruction were large and varied considerably across groups. The findings concerning allocation of vocational instructional resources were that pupils enrolled in non-vocational programs received more of vocational instruction resources than students enrolled in vocational programs. Females received more vocational instruction resources than males. It appeared black pupils received more vocational resources in academic programs, but less in vocational or general curricula. High school course track membership was found to be the major factor influencing a pupil's academic preparation for subsequent schooling and employment. This study concluded profound track-induced barriers to post-secondary access are built up due to the strong variation in course exposure over tracks. This occurred regardless of the ultimate aspirations of the students. (DWH)