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…

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…

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.…