Secondary analysis reduces the time and costs of obtaining and analyzing data and permits comparisons with other primary data. However, the original data may not be suitable for addressing current questions and may lack validity in relation to the phenomenon being studied. The Glueck data were collected during 1940-45 and included self- report data from each of the boys in the study, as well as data from parents, teachers, and official records. The authors' research analyzing the basic Glueck data illustrates the unlimited potential of secondary data analysis in the field of criminology. Their analysis also reveals that the basic Glueck data are valid and can be used in a substantive analysis. In addition, the analysis of predictive validity suggests a linkage between antisocial and delinquent behavior in early adolescence and criminality in late adolescence and young adulthood. Overall, the Glueck data can be used as independent measures of behavior or as general assessments of the juvenile's overall conduct. 34 references