University students' activities, thinking and learning during laboratory work

One aim of physics laboratory instruction is to help students connect theory to practice. So experiments are often chosen in order to 'demonstrate' specific concepts. Furthermore, students are expected to approach phenomena in a scientific way, that is, they should develop a hypothesis and plan their experiments accordingly. Although it is usually not stated explicitly, these instructional aims require that students have some conceptual knowledge before they start to carry out experiments. Otherwise, they would not be able to connect theory to practice or to develop a hypothesis. Empirical evidence from process-based studies of university students' labwork activities indicates that during practical work, students rarely express their conceptual knowledge explicitly. Rather, experiments seem to be the means by which students discover and 'stabilize' conceptual understanding when learning physics. Furthermore, students are much more likely to develop concepts that relate to similar events (phenomenon-based concepts) rather than concepts that arise from 'theories' (model-based concepts) which may explain their observations. Implications of these results for the design of laboratory activities are discussed.