Science is a social process—one that involves particular ways of talking, reasoning, observing, analyzing, and writing, which often have meaning only when shared within the scientific community. Discussions are one of the best ways to help students learn to “talk science” and construct understanding in a social context. Since inquiry is an important strategy for teaching science (NRC 1996; AAAS 1993), teachers face the challenge of facilitating meaningful discussions in an inquiry- or project-based setting. This article presents three types of discussions that can be used in inquiry-based activities and provides an example of each in a sample investigation.