Frequency counts of content emphases in each text section and laboratory exercise of the first commercial edition of the three versions of the BSCS materials were made in terms of the nine common BSCS content objectives. Two high schools used each version with teachers experienced in and trained for that version. Students were pre- and posttested with the BSCS Comprehensive Final Examination and the Processes of Science Test. Achievement of separate BSCS common objectives was measured by part tests consisting of items from each test designated by the BSCS test evaluation committee as related to that objective. Where an analysis of covariance indicated significant differences between achievement of students using each version, Scheffe post-hoc comparisons were made. There were significant differences in emphasis between the materials of each version, and between achievement of students taking each version. The group that achieved highest scores on an individual objective part test was not always the one that used the version giving greatest emphasis to that objective. In no test or part test did the group using the Yellow version score significantly less than a group using another version. (Author/AL)