Counterfactual conditional sentences (e.g., "If giraffes had fins, they would swim") involve an antecedent (e.g., "If giraffes had fins") which is false in the actual world. They also involve a consequent (e.g., "they would swim"), expressing a possibility given the antecedent. Reasoning about counterfactual…

This study investigates middle school students' reasoning about parallelism and perpendicularity of two line segments. Data were collected from 83 middle school students through an identification task consisting of various examples and non-examples of the parallelism and perpendicularity of two line segments. One-to-one interviews were also…

Developmental predictors of children's fraction concepts and procedures at the end of fourth grade were investigated in a 2-year longitudinal study. Participants were 357 children who started the study in third grade. Attentive behavior, language, nonverbal reasoning, number line estimation, calculation fluency, and reading fluency each…

The study examined the relation of language use and logical thought to social experience with both age and class held constant. The primary assumptions under study were: that the logic of symbolic grouping was highly sensitive to a child's experience with the objects to which that logic was applied; that the existence of diglossia in a bilingual…