The goal of the proposed study is to develop and validate an assessment tool to inform decision-making about social competence development in children. The Proactive Assessment of Social Skills (PASS) will consist of a brief and efficient direct measure of social competence in young children to chart the social growth and development of preschool children. This will include (a) screening all children for potential social/behavioral problems, (b) identifying children at risk for development of social/behavioral problems, and (c) evaluating the effectiveness of interventions for individual children and groups of children. The following research questions will be examined: (1) How well do scores on the PASS measure correlate with other measures of social competence (e.g., teacher ratings and naturalistic observations)? (2) Is the PASS a more sensitive measure of change in social skills than the PKBS as indicated by the production of a larger effect size over time? (3) Is the PASS able to discriminate between children ranked as low and high risk for social skill deficits? (4) What is the stability of children's performance on the PASS 2 weeks apart? and (5) What is the stability of children's performance across two activities? PASS is comprised of two components: an observational code and cooperative problem-solving activities. The observational code will encompass a frequency count within specific time intervals recording technique to code several key social skills that are acquired during the preschool years. The behaviors include: amount and quality of social turns, goal-oriented behaviors, on- and off- task behavior, and negative verbal and non-verbal behaviors. In addition, PASS consists of two 10 1/2 -minute cooperative problem-solving activities (e.g., Legos(c), blocks, Playdoh(c) , or puzzles) with same-age classroom peers in groups of three children. Three children will be assessed within each activity, rotating every 30 seconds for a total of 7 intervals (i.e. 3 1/2 minutes) per child. The two activities will be comparable and equivalent to control for variability. Participants will include 60 four-and five- year old children, their parents, and teachers recruited from Head Start programs in Lane County, Oregon. Trained observers will use the PASS to conduct eight observations during PASS cooperative activities to provide data regarding the reliability, validity, utility, and sensitivity of the PASS. Additionally, naturalistic observations, using the PASS observational code, will be used across 30 children from the Head Start sample. Head Start teachers will complete rating scales at the beginning and end of the study. Lastly, parents will be invited to participate in two parent focus groups. The focus groups will serve as a medium for parents to provide input and feedback at key points during the project (i.e. at beginning and at end). The researchers intend for the results of this project to contribute to the growing body of knowledge on effective identification of children at risk and prevention of the development of antisocial behavior. In addition, the PASS and training in using the PASS will be made available to Head Start teachers for identifying children at risk for developing social skills deficits.