Sex Differences in Strategy Use for Spatial Problem Solving in Chemistry

• In Event: Spatial Thinking in Chemistry

Abstract

Among the cognitive abilities that characterize individual and sex differences, visuo-spatial ability, specifically the ability to manipulate mental images, significantly impacts achievement in science ([NRC], 2006). Because students cannot perceive the phenomena under study, they are instead asked to employ strategies that include mentally manipulating internal representations. These imagistic strategies (Hegarty, 2004) are fundamental in scientific problem solving. Previously, Stieff and colleagues have shown that many spatial problems in chemistry can be solved through domain-specific analytical strategies (e.g, algorithms and heuristics) that allow successful problem solving without invoking mental images (Stieff, 2004, 2005, 2007; Stieff & Raje, 2010; Stieff, Stillings, Arasasingham, Taagepera, & Wamser, 2004). In this presentation, I explore the impact of strategy training by comparing changes in strategy use among students who receive instruction that emphasizes the use of analytical heuristics, imagistic strategies or both types of strategies. Additionally, I examine how men and women display different patterns of strategy use.

514 undergraduate students completed a 15-week introductory organic chemistry courses, one of three supplemental instructional units, and the Organic Chemistry Achievement & Strategy Choice Assessment (CASC) after instruction. Each instructional unit included 3 one-hour sessions and three independent assignments that emphasized the benefit of using either or both analytic and imagistic strategies. 157 students received the Analytical Unit, 159 received the Imagistic Unit, and 198 students received the Combined Unit. The CASC contained 12 items that asked students to identify molecular spatial relationships and to determine the outcome of molecular spatial transformations. Participants reported strategy use for each CASC item by selecting from a list of applicable strategies. Strategy categories included those that relied on reasoning via mental imagery (SI), external diagrams (SD), or heuristics that operated on either spatial information (SA) or non-spatial information (AL) (Stieff, Hegarty, & Dixon, 2010).

The number of self-reports for each category (SI, SA, SD, and AL) was analyzed via a 3 x 2 ANOVA with intervention and sex as between-subject variables. All students adopted more Spatial-Imagistic strategies in the Imagistic Unit compared to the other units, F(2, 509) = 23.93, p < .001; more Spatial-Analytic Strategies during the Analytic and Combined Units than the Imagistic Unit, F(2, 509) = 13.99, p < .001; more Spatial-Diagrammatic Strategies during the Imagery and Combined Units than the Analytic Unit, F(2, 509) = 23.93, p < .001; no differences were observed in Algorithm use among the units, F(1, 509) = 1.27, p = .28. In each semester, more males than females adopted Spatial-Imagistic Strategies, F(1, 509) = 4.11, p < .05; more females than males adopted Spatial-Analytic Strategies, F(1, 509) = 9.35, p < .01, and Algorithms, F(1, 509) = 5.02, p < .05; no difference in Spatial-Diagrammatic Strategy use was observed, F(1, 509) = 0.18, p = .57. The results suggest that strategy use can be directly trained and that no single type of strategy is requisite for problem solving in chemistry. More interestingly, the results show that men and women have distinct patterns of strategy use and respond differently to strategy training.

Author

• Mike Stieff, University of Illinois at Chicago