Reading and mathematics achievement and student self-concept were studied in 28 IGE elementary schools (schools using the system of Individually Guided Education). The data comprised 134 variables--input variables (student characteristics, teacher background, and expenditures for instruction); process variables (teaching time and school characteristics); and output variables (student achievement and self-concept). Several variables were consistently related to student achievement in reading or mathematics: (1) enrollment of teachers in a degree program (reading and mathematics achievement); (2) years of teaching experience (reading); (3) sex of the teacher (mathematics); (4) social maturity of students (reading); (5) social confidence of students (mathematics); (6) teachers' perception of the principal's leadership (reading and mathematics); (7) job satisfaction expressed by teachers (reading); and (8) teacher involvement in decision making (mathematics). A set of 12 independent variables accounted for 78 percent of the variance in reading achievement, and a similar set of 12 variables accounted for 71 percent of the variance in mathematics achievement. All of these variables were susceptible to control by teachers and administrators. Further research is needed before claims are made regarding implications for instructional practice. (Author/GDC)