Insights from the criminal-career and propensity positions suggest the value of a comprehensive means of incorporating theoretical variables in research on criminal careers, statistical models that yield meaningful projections relevant to public policy issues, and methods for comparing findings for various measures of offending. The authors present a conceptual framework that accomplishes this by applying the general linear model to the study of crime and criminal careers. This framework differentiates the elements of a curvilinear function that links the scale of the linear model and the scale of the measure of offending, a probabilistic relationship between a latent tendency to offend and the measure of offending, a probability distribution of individual differences on the latent dimension, and relationships among repeated observations for the same individual. The authors also describe numerous versions of the general linear model that do not require special statistical expertise and are appropriate for the full range of measures of offending. The article concludes with a discussion of strategies for comparing results across measures. 2 figures and 48 references