IQWST supports students constructing scientific explanations through two strategies. In the first students are presented with the claim-evidence-reasoning framework. The second strategy uses the characteristics of each of these components so that they can construct and evaluate explanations in terms of these components (e.g. asking themselves: is this evidence sufficient?).
The Rationale Behind the Feature (Specific Design Principle):
Krajcik et al., (this volume), refer to “construction of scientific explanations and arguments” as one of five scientific practices that should be considered when designing curriculum in science. One of the ways they suggest for supporting this practice is breaking it down into three components (McNeill et al., 2006; Moje et al., 2004). Based on Toulmin’s (1958) model, they refer to: a) Claim: a testable statement about some state of the world, b) Evidence: information or data that supports the claim, and c) Reasoning: a scientific principle that connects the claim to the evidence provided.
Context of Use:
Explanations are introduced in 6th grade with an emphasis on evidence. In 7th grade the focus is on the characteristics of reasoning. Students work through what makes a good scientific principle and the idea that their explanations must both state the principle and connect that principle to their evidence and claim. In 8th grade the students’ explanations get increasingly complex and there is a greater focus on alternative and competing explanations.
Field-based Evidence:
In a study to determine whether providing students with continuous written instructional support or fading written instructional support (scaffolds) better prepares students to construct scientific explanations when they are no longer provided with support, (see references), 331 seventh-grade students’ writing of scientific explanations during an 8-week, project-based chemistry unit in which the construction of scientific explanations is a keylearning goal was studied. The unit makes an of the CER framework as a support. Students received 1 of 2 treatments in terms of the type of written support: continuous, involving detailed support for every investigation, or faded, involving less support over time. The analyses showed significant learning gains for students for all components of scientific explanation (i.e., claim, evidence, and reasoning). However, on posttest items lacking scaffolds, the faded group gave stronger explanations in terms of their reasoning compared to the continuous group. Fading written scaffolds better equipped students to write explanations when they were not provided with support.
References:
Kali, Y., Fortus, D., & Ronen-Fuhrmann, T. (in press). Synthesizing TELS and CCMS design knowledge. In Y. Kali, M. C. Linn & J. E. Roseman (Eds.), Designing Coherent Science Education. NY: Teachers College Press.
McNeill, K. L., Lizotte, D. J., Krajcik, J. S., & Marx, R. W. (2006). Supporting Students’ Construction of Scientific Explanations by Fading Scaffolds in Instructional Materials. Journal of the Learning Sciences, 15(2), 153-191.
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