Three papers are presented in this monograph. The first--Trends in Process-Related Research on Curriculum and Teaching at Different Problem Levels in Educational Sciences--provides a re-analysis of research about the influences of certain environmental factors on student achievement. In the second paper--Frame Factors and Teaching for Mastery--the problem of mastery learning is reviewed from the point of view of the curriculum planner or evaluator. In the third paper--The Curriculum Development System in Sweden: Some Comments on Present Trends and Problems--phases in a reform cycle, frame factors, research, and policy-making are discussed. A bibliography is provided. (DS)