The purposes of this study were to examine the relationship between academic achievement and demographic and school background variables for school districts and school buildings and to develop from these relationships a basis for comparing achievement at similar schools. The sample consisted of Iowa public school districts that participated in the fall 1983 Iowa Basic Skills Testing Program at either the elementary or the junior high level, a total of 156 school districts. This included 356 elementary school buildings and 169 junior high buildings. Data were collected from the Iowa Department of Public Instruction, the National Center for Educational Statistics (1980 Census data), Iowa Testing Programs, and questionnaires completed by elementary and junior high school principals. Composite scores for fourth and fifth grades were combined to form an elementary school achievement score, and composite scores for seventh and eighth grades were combined for a junior high school achievement score. Regression analyses were performed separately for elementary and junior high levels to identify variables which significantly improved the prediction of achievement. Demographic variables were entered into the regression analyses first, followed by the school background variables. Results suggest that decisions made by schools do affect the achievement levels at the school. (Author/PN)