Indeed, instructional studies have documented success at teaching controlled experimental design to children in this grade span (see Klahr and Nigam, 2004; Toth, Klahr, and Chen, 2000).
As another example, consider the issue of reasoning about theory and evidence. In their delineation of the limitations on third to fifth graders’ scientific reasoning, the Benchmarks also claim that third to fifth graders “confuse theory (explanation) with evidence for it.” In accordance with this deficiency stance, most science curricula for young children avoid consideration of theory and evidence.
The developmental literature related to this fundamental aspect of scientific reasoning is more complex, with some studies in support of the Benchmarks stance and some studies suggesting greater competence. For example, Kuhn, Amsel, and O’Loughlin (1988) conclude that, in the preadolescent, theory and evidence “meld into a single representation as ‘the way things are’” (p. 221), whereas the research of Sodian, Zaitchek, and Carey (1991) indicates that, in some form and under some conditions, even preschoolers can make this distinction and reason accordingly.
Once again, the instructional literature indicates that children’s capabilities in this regard are to some degree amenable to instruction. The instructional design research literature provides an existence proof that elementary schoolchildren’s reasoning about theory and evidence in the context of doing science can be advanced under particular instructional conditions (see Smith et al., 2000). In Chapter 5 we discuss evidence related to both of these examples.
The problem with reducing the power and limitations of children’s scientific reasoning to developmental stages is further undermined by the enduring challenges that many of these issues have posed to much older students and even to practicing scientists. For example, although one can read Inhelder and Piaget’s work (1958) as contending that an understanding of experimental control emerges with formal operational thought, we continue to train students well beyond adolescence in the logic of experimental design. Continuing with the examples used above, the differentiation of theory and evidence poses even more challenges. Indeed, the philosopher of science Stephen Toulmin (1972) has argued that observation and theory are at some level inevitably entangled; in his words, “the semantic and empirical elements are not so much wantonly confused as unavoidably fused” (p. 189). Delaying instruction until such a capability emerges through “development” cannot constitute a strategic tactic, as development alone cannot adequately elaborate the competence. Furthermore, there is mounting evidence that instruction can advance these capabilities as well as many others.
In short, young children have a broad repertoire of cognitive capacities directly related to many aspects of scientific practice, and it is problematic to view these as simply a product of cognitive development. Current research