Algebraic thinking and strategy flexibility are essential to advanced mathematical thinking. Early algebra instruction uses 'missing-operand' problems (e.g., x - 7 = 2) solvable via two typical strategies: (1) direct retrieval of arithmetic facts (e.g., 9 - 7 = 2) and (2) performance of the inverse operation (e.g., 2 + 7 = 9). The current study…

This report describes several of the design decisions underlying ACT, a production system model of human cognition. ACT can be considered a high level computer programming language as well as a theory of the cognitive mechanisms underlying human information processing. ACT design decisions were based on both psychological and artificial…

Differences in critical thinking between undergraduate and graduate students in the social and mathematical sciences was investigated using multiple measures of critical thinking that reflect different types of problem structure. Educational level and academic area differences were found across measures. (Author/MLW)