A test battery was prepared for use in assessing the effectiveness of Head Start and similar programs in fostering young children's development. The instruments were designed to measure program effects on several dimensions of the cognitive, social-emotional, and applied strategies domains. Specific competencies measured are presumed to define in operational terms Head Start's overall goal of developing participating children's social competence. Each of the instruments is theoretically grounded, reflecting explicit conceptualizations of the domain and dimensions of behavior measured. All reflect hypotheses concerning sequential or hierarchical processes of development. Further, the measures are designed to accommodate the cultural diversity of Head Start and similar populations, and to identify the different but equally valid paths along which individuals, racial/ethnic groups, and sex groups of children progress toward common goals. With reference to the test battery, this report describes the areas of child development measured, and lists principles and procedures used in developing the instruments. The largest portion of the report presents rationales for and characteristics of the measures. The concluding section describes pre- and post-field testing, preliminary analyses of the data, and revisions of the instruments. Finally, features of the planned final form of the test battery are indicated. (RH)