Contents: Preface. P.J. Curran, A Latent Curve Framework for the Study of Developmental Trajectories in Adolescent Substance Use. S.T. Khoo, B.O. Muthén, Longitudinal Data on Families: Growth Modeling Alternatives. D. Hedeker, J.S. Rose, The Natural History of Smoking: A Pattern-Mixture Random-Effects Regression Model. B.O. Muthén, Methodological Issues in Random Coefficient Growth Modeling Using a Latent Variable Framework: Applications to the Development of Heavy Drinking Ages 18 Through 37. D.P. MacKinnon, Contrasts in Multiple Mediator Models. P.K. Wood, Estimation and Equivalent Models for Quadratic and Interactive Latent Variable Models. J.B. Ullman, J.A. Stein, R.L. Dukes, Evaluation of D.A.R.E. (Drug Abuse Resistance Education) With Latent Variables in the Context of a Solomon Four Group Design. D.C. Rowe, J.L. Rodgers, M. Gilson, Epidemics of Smoking: Modeling Tobacco Use Among Adolescents. S.L. Hyatt, L.M. Collins, Using Latent Transition Analysis to Examine the Relationship Between Perceived Parental Permissiveness and the Onset of Substance Use. J.S. Rose, L. Chassin, C.C. Presson, S.J. Sherman, Prospective Predictors of Smoking Cessation: A Logistic Regression Application. C.C. Presson, L. Chassin, S.J. Sherman, J.S. Rose, Summary and Future Directions.