In this article I explore the interrelated contributions of different modes of meaning making to the interaction between an adult and two young students around a science experiment involving refraction, henceforth referred to as the shoebox'' experiment. The event, which I shall describe in more detail below, was videorecorded in 1992 in a classroom of grade three and four students in an elementary school serving a multiethnic population in downtown Toronto. I was both the camera operator and the visiting adult. Some years later, I selected the videotape of the shoebox experiment as the basis for practical work in my graduate class on discourse analysis. There were two reasons for choosing this material. The first was because of its completeness as the record of the various stages of an activity, from initial selection by the two children to the writing of the texts in which they reported what they had done and learned; the second was that, as I had been the visiting teacher,'' I would be able to offer a participant's perspective and also to encourage the sort of critical analysis of the interaction that would have been ethically less acceptable if another teacher had been involved. As it turned out, both these expectations were fulfilled, though the second not exactly as I had anticipated Γ as I shall explain below.