This study compared the process skill achievement of students (N=107) completing traditional laboratory exercises with students (N=127) not only completing the same exercises but also receiving instruction in such integrated process skills as identifying variables and stating hypotheses. The relationships among process skill achievement, cognitive development, overall course achievement, sex, and attitudes were also examined. Results indicate that emphasis on process skills in the laboratory can significantly improve process skill achievement. Students with lower levels of cognitive development had a lower level of process skill achievement, but there was no difference in gain in process skill achievement across levels of cognitive development. Females on the average had a slightly lower level of cognitive development than males, but there was no sex difference in process skill achievement overall. However, statistical interactions indicated that females at the lowest level of cognitive development scored higher on some of the process skill measures than did males at the same level of cognitive development. In general, this study indicates that, along with gains in content achievement, process skill achievement can be improved in students at all levels of cognitive development through reasonable modifications of existing laboratory exercises. (Author/JN)