The report, based on a 1974 sample of 47,000 households, describes the school enrollment of older adults working toward a high school or college diploma or a trade school certificate. Data, summarized in narrative and tabular form, show that two-thirds of the one and one-half million students age 35 and over in the United States were enrolled in college (including 285,000 in graduate school), and about 400,000 were attending trade or vocational school. The remainder (80,000) were enrolled in high school. About 14% of the adults in school were black. Women students in the group generally had higher labor force participation rates, age for age, than women in the population as a whole. Younger male students in the group had rates similar to those of their nonstudent contemporaries. The rate for male students 45 and over was substantially higher than for nonstudents. This finding suggests that older persons in school had a very strong attachment to the work force, and their school enrollment was therefore ancillary to career development. A four-page explanatory note briefly describes the basic labor force concepts, sample design, estimating methods, and reliability of the data. (Author/MS)