The measurement of statistical reasoning in verbal-numerical and graphical forms: a pilot study

Numerous subjects have trouble in understanding various conceptions connected to statistical problems. Research reports how students' ability to solve problems (including statistical problems) can be influenced by exhibiting proofs. In this work we aim to contrive an original and easy instrument able to assess statistical reasoning on uncertainty and on association, regarding two different forms of proof presentation: pictorial-graphical and verbal–numerical. We have conceived eleven pairs of simple problems in the verbal–numerical and pictorial–graphical form and we have presented the proofs to 47 undergraduate students. The purpose of our work was to evaluate the goodness and reliability of these problems in the assessment of statistical reasoning. Each subject solved each pair of proofs in the verbal-numerical and in the pictorial–graphical form, in different problem presentation orders. Data analyses have highlighted that six out of the eleven pairs of problems appear to be useful and adequate to estimate statistical reasoning on uncertainty and that there is no effect due to the order of presentation in the verbal–numerical and pictorial–graphical form.