A framework for conceptualizing young children's theoretical and task-related strategies in everyday situations is presented in this Head Start final report. The first section of the report discusses the concept of strategies, reviews relevant literature, and presents a theoretical model of the organization of strategic behavior. The second section describes the Children's Strategies Assessment System (CSAS), a tool for assessing young children's competence in social interactions and in material tasks. The CSAS is largely based on Bronson's (1974, 1982) concept of "executive skill" and on her classroom observation measure, the Executive Skill Profile for Preschool and Primary School Children. The CSAS also extends the social and mastery strategies of Bronson's work, integrating these within a unifying theoretical base and including strategies which have negative as well as positive effects. In the third section of the report, a brief account is given of the evolution of the Animal Stalls task (AST) in its first, second, and current versions. The AST is a block construction task, utilizing familiar materials and an unfamiliar problem, which can be adapted to different ages. In the fourth section, the analysis of pilot test data gathered from over 100 children is presented and discussed, and directions for future research are specified. Related materials, including a copy of the CSAS, are appended. (RH)