Students' Overuse Of Proportional Reasoning:Cognitive Mechanism And Intervention

The overuse of proportional reasoning refers to the fact that after learning and mastering the proportional strategy,students can easily ignore specific problem situation in problem solving,and inappropriately use proportional reasoning on non-proportional problems,which leads to a failure of problem solving.This study regards the inappropriate use of proportional reasoning as a heuristic bias.Correctly solving the problem requires inhibiting this heuristic bias.The role of inhibit control in overcoming the misleading of the proportional strategy can be verified by using the Negative Priming(NP)paradigm.However,there has been no study to investigate the cognitive mechanism of the biased-reasoners(misleading by proportional reasoning)and whether it can help students overcome heuristic bias through appropriate intervention.The present study included three experiments.In Experiment 1,235 primary and middle school students were selected as the study subjects.Participants were asked to complete a picture reasoning task based on NP paradigm and a self-confidence rating scale in order to know whether heuristic bias should be attributed to the failure of inhibiting the misleading strategy or the absence of conflict detection between the problem situation and the proportional strategy.The results showed that there was a significant negative priming effect in the visual reasoning task indicating that inhibiting proportional reasoning is needed when solving non-proportional problems.We found a confidence decrease after they erroneously solved the non-proportional problems.This indicates that students could detect a conflict when they applied the proportional heuristic inappropriately.Based on the results of Experiment 1,Experiment 2 compared the working memory capacity and the distractor inhibition capability between the bias reasoner and the non-bias reasoner for solving why the bias reasoner cannot effectively inhibit the misleading of the proportional strategy.Our results showed that unbiased-reasoners had a higher WMC than did biased-reasoners,but their distractor inhibition capability did not differ fromeach other.This indicated that the failure of inhibiting heuristic was related to low executive resource rather than poor distractor inhibition ability.Experiment 3examined whether it is possible to improve students' performance on picture reasoning task by a warning intervention.The results showed that the intervention did not improve the performance of the additive problems,but improved the efficiency of inhibitory control.According to our findings,we concluded that:First,students failed to solve the non-proportional problems because they could not inhibit the proportional heuristic but not because they could not detect the need of inhibition in the first place.Second,the working memory capacity of the bias reasoner was significantly lower than that of the non-bias reasoner,but there was no significant difference in distractor inhibition capability between the two groups.It shows that WMC,as a limited cognitive resource,had a fundamental impact on the execution of the inhibitory mechanism.Third,the intervention didn't improve the performance on non-proportional problems,but improved the efficiency of inhibitory control.