DESCRIPTORS *Academic Achievement; Elementary Education;

The Team-Assisted Individualization (TA1) mathematics program has been developed in an attempt to make individualized instrulation workable in the classroom by adding components of coopeegtive learning. This paper Presents the rationale for the development of TAI and deScribes results of three field experiments conducted to assess the effect of TAI on student achievement,, attitudes, and behavior. The experiments, which involved a total of 1,997 students in grades 3 through 6 (including mainstreamed students), demonstrated basic achievement effects of the program and a number of positive social and attitudinal effects. Results clearly indicated that TAI increases students ' mathematics achievement more than traditional instructional methods and that TAI students gained more than their control counterparts on every achievement measure in every study, although,the differences were not statisticall