This document praises the Comprehensive Preschool Education and Child Day-Care Act and advocates an equally comprehensive collateral program of research and evaluation. In order to avoid delay in starting preschool and child care programs, the research undertaken should be of the kind called evaluative research in which program and research are in progress simultaneously. The research model is therefore integrated into the program and focuses on process as well as product measures. Although traditional research has followed an engineering model, the research associated with these preschool programs should follow a medical model. The implications of a medical model include assessment of both intended and possible outcomes, and frequent monitoring of participants' feelings and program processes. An example of such research is the Head Start longitudinal study of disadvantaged children being carried on by Educational Testing Service. Included is a description of some of the problems encountered in this project. (MH)