Towards the development of problems comparing verbal-numerical and graphical formats in statistical reasoning

Many students struggle with understanding concepts related to statistical problems. A body of studies has stated that the attitude of undergraduates when resolving statistical problems can be affected by problem displaying methods. Our paper reports on the development of novel and accessible problems designed to compare the basic processes of statistical reasoning using two different methods of presentation: Verbal-numerical versus graphical. Therefore, the main purpose of the current study is to estimate the goodness and reliability of those problems. Thus, we carried out two pilot studies in Italy and Spain, respectively. In the first study, 95 undergraduate students from the University of Cagliari (Italy) were presented with eleven pairs of simple statistical problems, homologous for verbal-numerical and graphical formats. Hence, according to the outcomes, we modified and improved the structure of our problems in order to present the revised version to 148 undergraduate students of the University of Barcelona (Spain). Each undergraduate was asked to solve the paired problems presented in verbal-numerical and graphical format, so that the presentation order of the trials was counterbalanced for all the participants. The results suggested which problems are suitable to assess the basic processes underpinning the statistical reasoning. Furthermore, by analysing the open responses on reasoning leading to the solution of the above mentioned problems, we were able to understand which items were misunderstood by our participants in order to reformulate them. Lastly, we discuss the method used to articulate the new items and the direction for future research.