The data for this research were based on the longitudinal study for the High School and Beyond for 1980 and 1982. Over 1100 public and private schools were selected for the first stage, and 36 students were chosen from each school in the second stage. Inclusiveness, electivity, and school SES composition were all found to influence track placement. Academic inclusiveness affects the initial track placement, subsequently affecting achievement as well. School SES is a direct reflection of the community around it, and it mirrors this fact by having higher numbers of students tracked in the predominant ability-level represented by the community.
Research has, then set out to prove that one form of mixing students works better than another.
Colquitt County High School. A Framework for High School Science Education. Georgia Department of Education. National Committee on Science Education Standards and Assessment. National Science Education Standards.