title: Operand-order effect in multiplication and addition: the long-term effects of reorganization processand acquisition sequence.
abstract: Butterworth, Marchesini, and Girelli (2003) showed that children solved multiplications faster when the larger operand was first (e.g., 5 · 2) than when the smaller operand was first (e.g., 2 · 5). This result was interpreted according to the reorganization hypothesis, which states that, as children begin to switch from counting-based strategies (e.g., repeated additions) to direct retrieval, non-retrieval strategies generate an advantage for the larger-operand-first order. In two experiments we showed that order preferences also persist into adulthood. With additions, the larger-operand-first order was solved faster than the inverse order. With multiplications we obtained a novel result: Largeroperand-first problems were solved faster when at least one operand was smaller than 5, whereas smaller-operand-first problems were solved faster when both operands were larger than 5. Since the reorganization process alone cannot explain our results, we propose that order preferences are also influenced by the sequence in which the members of a commuted pair are acquired.
authors: Department of Psychology and Cognitive Science, University of Trento, <location>Italy</location> College of Research Methodology and Cognitive Science, Burapha University, Chonburi, <location>Thailand</location>
authors: Daniele
authors: D
authors: Didino
authors: Department of Psychology and Cognitive Science, University of Trento, <location>Italy</location>
authors: Luigi
authors: L
authors: Lombardi
authors: Department of Psychology and Cognitive Science, University of Trento, <location>Italy</location>
authors: Francesco
authors: F
authors: Vespignani
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D055641:Mathematical Concepts; D008606:Mental Processes; D011340:Problem Solving; D013997:Time Factors
keywords: direct retrieval; non-retrieval strategies; operand-order effect; production task, verification task