The authors propose a strategy for studying the effects of time-varying instructional treatments on repeatedly observed student achievement. This approach responds to three challenges: (a) The yearly reallocation of students to classrooms and teachers creates a complex structure of dependence among responses; (b) a child's learning outcome under a…

The study reported here was begun in 1955 by a group of five staff members in the Elementary Schools Section, U. S. Office of Education. The purpose was to find out and report: (1) what research says about children a 9,10, and 11; (2) what educators say about today's children in grades 4, 5, and 6, and (3) some good educational practices for…