Do we perceive correctly whether a 2-D object is balanced or unbalanced? What would be the cause of biased equilibrium judgments? In two psychometric studies, we varied independently the characteristics of the objects and the equilibrium states. First, we observed that observers were excessively sensitive to the eccentricity of the object top.…

During the late 1970s and 1980s, as interest in Lev Vygotsky's work was growing rapidly, most of his writings were unavailable in English. Translations of Vygotsky's work that reflect the breadth and depth of his thinking became available in the mid-to late 1990s. However, this work has yet to become an integral part of educational psychology.…

We investigated children's ability to generate associations and how automaticity of associative activation unfolds developmentally. Children generated associative responses using a single associate paradigm (Experiment 1) or a Deese/Roediger-McDermott (DRM)-like multiple associates paradigm (Experiment 2). The results indicated that children's…

To date, a number of studies have demonstrated the existence of mismatches between children's "implicit" and "explicit" knowledge at certain points in development that become manifest by their gestures and gaze orientation in different problem solving contexts. Stimulated by this research, we used eye movement measurement to…

Items commonly belong to many categories. Cross-classification is the classification of a single item into more than one category. This research explored 2- to 6-year-old children's use of 2 different category systems for cross-classification: script (e.g., school-time items, birthday party items) and taxonomic (e.g., animals, clothes). The…

This study examined the generality of the logarithmic to linear transition in children's representations of numerical magnitudes and the role of subjective categorization of numbers in the acquisition of more advanced understanding. Experiment 1 (49 girls and 41 boys, ages 5-8 years) suggested parallel transitions from kindergarten to second grade…

A general theory of how children learn conservation concepts is presented. The acquisition process is described at an abstract level in terms of a rule-sampling system, implying a three-state Markov model with identifiable parameters. Three experiments testing the model's quantitative predictions about conservation learning experiments are…

A conservation problem of numerical equivalence which 80% of adults reliably fail and 40% of third graders pass was developed, and responses of 188 subjects (Grades 2, 3, 5, 7, 9, 11 and college) to it and related number conservation and probability problems indicated that the differences in nonconservation were rooted in subjects' different…

This paper examines ways in which coherent reasoning about key concepts such as variability, sampling, data, and distribution can be developed as part of statistics education. Instructional activities that could support such reasoning were developed through design research conducted with students in grades 7 and 8. Results are reported from a…