Investigated was the effect of different types of laboratory reports on measured outcomes of the Chemical Education Materials Study (CHEMS) Chemistry. Compared were procedures using essay laboratory reports, mimeographed laboratory sheets prepared by the investigator and completed by the students, the laboratory manual for the course completed by the students, and no report at all. The mimeographed laboratory sheets group was superior on the CHEM Study Semester Final, but there were no significant differences between the groups on the other tests. (GR)