A sample of 210 class-two (grade 8) students from six randomly selected classes from six Nigerian schools was divided into two (experimental and control) groups. Using materials from some units of the Nigerian Integrated Science Project (NISP), the experimental group was taught by a laboratory method while the control group was taught by the lecture method. Data were collected using an Achievement Test for Integrated Science Students developed by the authors and student ability was measured by tests secured from the Department of Teacher Education, University of Ibadan. In analyzing the data, an analysis of covariance was employed. T-test statistics were also used to determine significant difference between means of different groups.

High achievers of both groups had identical achievement, but the low achievers in the experimental group performed better than their counterparts in the control group. While the study showed that males in this study prefer laboratory method to lecture method when compared with their female counterparts, the study also revealed that females in the control classes performed better than males of the same group.