Table 1 presents a set of claims and supporting evidence
derived from the analyses of observational and artifact data
collected on five identified students in one fourth-grade
classroom. This class was engaged in the GIsML program
of study that examined why objects sink and float. Much of
the investigation focused on (a) constructing and manipulating
the Cartesian diver system (CDS),4 (b) working within
small groups to construct an explanation for how it is that
the diver within the CDS can both float and sink, (c)
designing posters to share the group’s explanation with the
class, and (d) participating in whole-class presentations and
discussions regarding the CDS.