This article discusses the research potential for some of the National Center for Educational Statistics' data sets, specifically those focused on junior and senior high school students. All share some characteristics, but it is the most recent (National Education Longitudinal Study: 1988) (NELS:88) which is the most comprehensive. Since data is gathered not only from the students themselves, but parents, teachers, and school administrators, researchers can begin to put the educational process "in context" and include extra classroom factors in their analyses. Data are available on CD-ROMs, a format that has advantages as well as limitations. Given the fact that NELS:88 began when the students were in the eighth grade, it is possible to study the gender gap in mathematics and science. Missing data, internal inconsistencies, and lack of school contextual data are problems. In addition, as presently constructed, these data sets cannot be used to study students attending schools in the very large cities. (Contains 2 tables and 21 references.) (Author/SLD)