A Procedural Problem in Laboratory Teaching; Experiment and Explain, or Vice-Versa?

This work describes two different approaches to teaching the laboratory segment of a freshman chemistry course. In Approach I, each experiment was explained and demonstrated to the students before they participated; the expected results were also discussed. In Approach II, the students conducted the experiments themselves with minimal help from the instructor. Students were surveyed regarding their perceptions relative to understanding, enjoyment, achievement, and the difficulty of conducting the experiments. While 54% of the students reported increased understanding using Approach II, only 32% reported similarly following Approach I. However, 78% of the students indicated that they felt a sense of achievement using Approach II, and 76% agreed that conducting experiments independently became routine or almost routine. The data showed that all students with high quiz grades (≥ average + 1.5 of the standard deviation of the class) preferred to do the experiments first, while only 17% of students with low gr...