One goal of the Classroom InSiTE project (Cowie, Moreland, Jones, & Otrel-Cass, 2008)1 was to enhance classroom interactions as part of teacher assessment for learning. Research and development for assessment for learning has tended to focus on the role of talk and the role of written feedback. Less attention has been paid to the other modes that people use in everyday communication such as the role of gesture, drawing, visual images, and action. Students, more now than ever before, live in a multimodal world: websites, mobile technologies and even books and magazines are sites of “complex hybrids and fusions of visual and verbal meaning making resources” (Lemke, 2004, p. 42). Research evidence is accumulating as to the key role for diagrams, pictures, and other nonlinguistic representations in illuminating curriculum content, and supporting the achievement of diverse learners (Alton-Lee, 2003). Classroom studies in science and technology education are only just beginning to explore how teachers and students use multiple modes to develop and express ideas and skills. In science education, for example, Kress, Jewitt, Ogborn, and Tsatsarelius (2001) provide a detailed account of how a science teacher used gestures, drawings, science diagrams, a three-dimensional model, and images to demonstrate to students the circulation of blood. In this article we provide evidence from the InSiTE study that effective teacher–student interaction utilises multiple modes to express ideas and enhance student learning.