The National Education Longitudinal Studies (NELS) program is a long-term effort that now encompasses the educational experience of youth from three decades, the 1970s, 1980s, and 1990s. The NELS program studies the educational, vocational, and personal development of students at various grade levels, and the personal, familial, social,…

A framework for understanding methodological practices from the perspectives of internal validity, external validity, statistical control validity, and construct validity is presented. One hundred doctoral dissertations completed between 1980 and 1988 at a single urban public university were analyzed for various methodological practices and types…