L'euristica dei contrari nel problem solving geometrico

Contemporary researches, that have dealt with problem solving conceived as process of reasoning implied in the solution of tasks in which an inference must be produced (for a review Mercier & Sperber, 2011), have focused the cognitive dimension of this process, underling the involvement of other cognitive abilities, such as intelligence, intellect, attention and working memory. These studies have neglected the role of perception in processes of thinking involved in the solution of problem solving tasks. Nevertheless, this aspect has been emphasized by contemporary researches about learning geometry (Duval, 1995, 1999, 2006; Gorgorio, 1999; Gray, 1999, Gutierrez, 1996a, 1996b) and by studies about insight in problem solving (Knoblich, Ohlsson, Haider, & Rhenius, 1999; Ӧllinger, Jones, Knoblich, 2006, 2008) that, recalling what has been highlighted by Gestalt psychology (Wertherimer,1919/1945; Duncker,1935, 1945), have underlined the importance of perceptual- figural aspects in problem solving. This research aims toinvestigate the role of perceptual aspects of a problem in a geometrical problem solving focusing on how the attention and the manipulation of spatial contraries modify the process of solution. The study carried out consisted of a problem solving task in which 240 participants, divided in 80 interobservational groups (Bozzi, 1978), were asked to solve six geometrical problems. The experimental design was composed by four conditions: a) a control condition where no specific suggestions were provided (baseline condition), b) a condition where participants were asked to search spatial contraries related to the problem before embarking on the process of solution; c) a condition where participants were asked to search spatial contraries before embarking on the process of solution and they were informed that contraries could help the solution process; d) a condition where participants were invited to use all prior acquired notions to solve the problems. The analyses of the solution time, the typology of solutions provided and the solution process have demonstrated that using a heuristics based on contraries affects the process of solution: it reduces the solution time as well as the suggestion to use their prior notions to find a solution does, it increases the number of perceptual solutions, and influences the strategies used in the solution process.