The conclusions are reported of a survey of aspects of school and classroom environments and their effects on student achievement as these effects were indicated by data from the International Association for the Evaluation of Educational Achievement (IEA) study of schools in the United States. Only the resource levels and activities generally available in the school as a whole could be investigated. Subjects were 10 or 14 years old or were high school seniors. No association was found between achievement levels and either hours of school per week or weeks of school per year; but hours in specific subject areas had consistent positive relationships with achievement and often with positive attitudes in those areas. There appeared to be threshold levels of resources below which adequate school achievement could not be accomplished; but schools with high resource levels exhibited a full range, low through high, of achievement. The relationships between achievement and student activity or participation, degree of structure, and amount of evaluation activity in the schools were complex. (Author/CTM)