The major purpose of this study was to determine whether science process achievement tests could be developed which could be administered to groups of primary grade pupils. Tests developed were a series of 35mm color slides which illustrated laboratory situations involving basic science processes. The slides were synchronized with a tape recording to provide instructions for the children. Each pupil indicated his answer to each question by marking his answer sheet as directed from the tape recording. Six samples of the Basic Science Process Tests (BSPT) were developed. Each BSPT item was validated by a critique jury. Data were collected on 854 pupils in grades 1, 2, and 3, half of whom had studied the 1967 edition of "Science - A Process Approach" for one year. Evidence from this study indicates that the test format used can be made to function effectively as a group test for primary grade children. Pupils reacted favorably to the BSPT and seemed to be able to respond appropriately to the format and to individual items. (BR)