This guide is designed to assist States, agencies, and/or facilities who work with youth who are neglected, delinquent, or at-risk (N or D). The information in the guide will benefit those who are (a) interested in implementing pre-posttests, (b) in the process of identifying an appropriate pre-posttest, or (c) ready to evaluate current testing procedures. Within this guide, the reader will find basic information on what pre-posttests are, why facilities should implement pre-posttest procedures, characteristics of different pre-posttests, and how agencies can use the information from their assessment practice. With an increasing number of different pre-posttests available, it is important that facilities understand how to identify the pre-posttest best suited for the needs of their unique youth population.