Examined social influences on the reasoning and rhetorical strategies of fourth graders. Found that the use of argument stratagems snowballed, there were fewer and fewer lines of discussion between successive appearances of a stratagem, and the snowball phenomenon was more pronounced during discussions with open participation than during…

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.…

Fourth, sixth, and eighth graders and adults estimated answers to multiplication problems and explained their estimation procedures. Found performance improved with age, and sixth graders understood the simplification principle in estimation. The most striking developmental changes were in conceptual knowledge used for estimating. Proposes a…

Devised a model that hypothesized that students, in discriminating relevant information in mathematical story problems, search for values of semantic categories that match those in the problem. Two experiments assessed the validity of the model. Results indicated that the model was an accurate predictor of discrimination performance for successful…

Examined the cognitive processes through which writing contributes to science learning among elementary school students. Analyzed four aspects of students' verbal learning strategies: writing operations, transitional sequences among writing operations, text features, and strategies for generating content. Concluded that for elementary students,…

This case study examined changes in a fifth-grade mathematics classroom in Hong Kong when a video-based story involving mathematics problem solving was introduced. Findings suggest that new technologies not compatible with existing practice may lead to intense reflections about which aspects of the individuals, their environment, and the new…

First of three experiments compared third graders who had studied worked, two-step arithmetic word problems to those learning through conventional problem solving. The former grouped showed superior test performance. In experiments two and three, children presented with integrated worked examples outperformed those presented with split-source…

Two experiments examined the use of a number-line metaphor presented with interactive multimedia to help sixth graders with varying levels of mathematics achievement or spatial ability build connections between addition and subtraction of signed numbers and existing conceptual knowledge. Results indicated that use of multiple representations…

This study explored first graders' fraction learning when the teacher elicited and built on children's informal knowledge of fractions during discussions of equal-sharing tasks; the study focused on key classroom interactions resulting in cognitive change. Findings suggest that thinking about fractions is influenced by the structure of the child's…

The study examined children's understanding of scientific inquiry, through the lens of their conceptualization of uncertainty in investigations they had designed and implemented with a partner. These largely student-regulated investigations followed a unit about animal behavior that emphasized the scaffolding of independent inquiry. Participants…