This document contains the report of the Unified Science and Mathematics for Elementary Schools (USMES) evaluation team on the 1974-75 investigation of the cognitive and affective responses of students to USMES, an interdisciplinary, process curriculum designed to develop the problem solving abilities of elementary school students. Included in this evaluation of USMES are the results of a pre-post control group design to assess the curriculum's effect on students' basic skill development, their attitude change, and their progress in complex problem solving as measured by small group performance on real-life relevant, simulated problem tasks. The results of interviews with USMES teachers and students, unstructured observations during site visitations and field staff's documentation of USMES usage are also included in this report. (Author/MV)