Abstract:

This research inquires some dimensions implied in the “graphical facilitation effect” on probabilistic reasoning, considering the associations of performance with contextual and individual features. Indeed, many authors highlighted that graphical representations might enhance problem solving in probabilistic reasoning; however, the cognitive processes underpinning these aspects have to be further deepened. Specifically, the role and the interaction between contextual and individual dimensions are not yet clearly defined.

We aim to enlighten the influence of these kinds of dimensions, comparing the probabilistic reasoning applied by the same undergraduate in similar problems presented in verbal-numerical and graphical-pictorial formats. These assessments were conducted by controlling the effects on performance of numerical and visuo spatial abilities, attitudes towards statistics, statistical anxiety, and metacognitive awareness of the correctness of response (confidence); furthermore we considered the influence of time pressure (presence versus absence) and of the type of university course enrolled (Psychology versus Business and Economics).

Three hundred and forty-five Italian first year undergraduates, lacking statistical expertise, fulfilled a protocol composed by standardized instruments of assessment. The evaluation of accuracy on the solution in both formats have been related to the aforementioned contextual variables (time pressure, university course enrolled) and individual variables (abilities, anxiety, attitudes and confidence).

At first, Hierarchical Linear Regressions were carried out separately to identify the individual variables affecting performance. Two formats of problem presentation were used. Then, the Analysis of Covariance with Mixed Design was applied, in order to highlight the effects of covariates (identified as the significant predictors distinguished in the previous regressions), the effects of the between factors (time pressure and university course) on the performance in two formats (considered as repeated measures).

It was observed that confidence is the finest predictor of performance accuracy in both formats; it means that the metacognitive dimension strongly affects accuracy. Furthermore, the effect of format was underlined ( “graphical facilitation” was highlighted) and the effect of time pressure was emphasised (the presence of time limits significantly enhances performance). No differences were found between the undergraduates enrolled in two university courses (Psychology and Business and Economics).

In summary, “graphical facilitation” might be the aftereffect of multifactorial relations between different variables. Furthermore, these findings might be considered as an evidence of the key role of individual differences in probabilistic reasoning, which, by interacting with contextual dimensions, might influence the application of strategies useful to solve probabilistic problems, specifically in undergraduates without any statistical knowledge.

Keywords:

Probabilistic reasoning, Verbal-numerical and graphical-pictorial format, Contextual and individual variables.