Exhibits in informal science institutions, like science centers and museums, are often designed to help people learn, but research showing the immediate impact of experiences with exhibits on understanding is limited. This dissertation tested the hypothesis that the value of first-hand experience with an exhibit is not necessarily in its immediate impact on understanding the topic it addresses, but rather in providing the foundation for understanding in the future. The study was guided by the Preparation for Future Learning (PFL) framework (Bransford & Schwartz, 1999), which was applied to a sixth grade class field trip to a science museum (N = 243). A goal of the field trip was to learn about mechanical advantage by engaging with a Giant Lever exhibit. The PFL framework predicted that students who noticed differences in contrasting cases of mechanical advantage at the exhibit and then attempted to explain the reason for the differences would learn better from an expert explanation heard later in school than their peers who engaged with the exhibit in different ways. A quasi-experimental 2 x 2 x 2 factorial design allowed the effects of three independent variables to be examined: first, kinesthetic vs. observation activity as the mechanism to notice the contrast; second, attempting to explain differences vs. not making the attempt; third, hearing an expert explanation in school vs. not hearing it. The dependent variable was conceptual understanding. Results indicated, unexpectedly, that kinesthetic experience and observation of peers were equally effective in helping students to notice differences in mechanical advantage among several lever configurations. As expected, producing a response to explain the differences predicted understanding only for students who subsequently heard the expert explanation at school the following day. Likewise, hearing the explanation only predicted understanding for students who had attempted to explain the phenomenon beforehand. The results provide support for the PFL framework and for the position that learning from exhibits in science museums is most evident when subsequent reinforcing events (Falk & Dierking, 2000), such as the explanation in school, are taken into account.