The Comprehensive School Mathematics Program (CSMP) is a program of CEMREL, Inc., one of the national educational laboratories, and was funded by the National Institute of Education (NIE). Its major purpose is the development of curriculum materials for the elementary grades. Beginning in 1973, CSMP ran an extended pilot trial of its elementary program. The 1976-77 period was the fourth year. This material describes the results of some individually conducted tests with third graders in the St. Louis region. The purpose of this testing was to achieve a deeper understanding of the mathematical processes used by CSMP versus non-CSMP students than paper-and-pencil testing allows. It is noted that a great deal of information has been summarized very briefly. Results indicated very real differences in favor of CSMP students on a relatively small number of items, but for many of the tasks the differences were not considered large enough to be of importance, particularly in view of the small numbers of pupils tested. It is noted that the study was exploratory, with hopes that a more efficient procedure would be adopted in the future to further probe some of the findings. (MP)