This study attempted to determine if students learn science concepts better when laboratories are used to verify concepts already intorduced through lectures and textbooks (verification laboratories or whether achievement and retention are improved when laboratories are used to introduce new concepts (directed discovery learning laboratories). The study specifically examined whether seventh-grade earth science students (N=103) introduced to science concepts through laboratory exercises, followed by textbook readings and classroom discussions, learned and retained these concepts better than students who had the concepts introduced through textbook readings or teacher lectures followed by verification laboratories, and if these students also had a stronger preference for science than the latter group of students. Results indicate that students did experience greater achievement and retention when directed discovery learning laboratories were used to introduce new concepts than they did when the same concepts were taught using the laboratory activities for verification. The difference in preference for science between experimental and control groups was not significant. (Author/JN)