One obstacle to understanding abstract concepts such as the "control of variables" strategy (CVS) is the tendency for learners to focus on surface rather than deep features in instructional materials. However, in tasks such as learning CVS, these same surface features may also support understanding, provided learners realize the…

Many studies have shown benefits associated with engaging students in problem-solving activities prior to administering lessons. These problem-solving activities are assumed to activate relevant knowledge and allow students to develop some initial knowledge structures, which support understanding of the lesson. In this paper we report the results…

Fourth- and fifth-graders were taught how to design simple unconfounded experiments using one of two instructional methods differing only in whether children manipulated physical or virtual materials. Results indicated that the two types of materials were equally effective in achieving several instructional objectives, including the design of…

Examined 7- to 10-year-olds' ability to acquire a domain-general processing strategy--Control of Variables Strategy (CVS)-- and make valid inferences. Found that with explicit training within domains and probe questions, children could learn and transfer the CVS. Probes without direct instruction did not improve CVS and inferential thinking…

Nine- through 14-year-old girls made predictions about and performed experiments involving sinking objects. Found that children initially believed that weight alone determined an object's sinking rate, older but not younger children viewed experimentation as a way of exploring object attributes other than weight, and experimentation helped…

Hands-on science typically uses physical materials to give students first-hand experience in scientific methodologies, but the recent availability of virtual laboratories raises an important question about whether what students' hands are on matters to their learning. The overall findings of two articles that employed simple comparisons of…

Studied developmental differences in the search constraint heuristics used in scientific reasoning using 12 undergraduates, 20 community college students, 17 fifth to seventh graders (grade 6), and 15 third graders taught to use a programmable robot. Adults use domain-general skills that go beyond the logic of confirmation and disconfirmation.…

Developed and tested a cognitive theory-based intervention teaching a procedure for designing simple controlled experiments to fourth graders. Found that the intervention produced significant gains in students' ability to create controlled experiments, provide valid justifications for their experiments, and evaluate experiments designed by others.…