Teaching box plots: An intervention using refutational text and multiple external representations

Despite the omnipresence of box plots in education and research, many misinterpretations have been reported on this representation for data distributions. Previous studies did not succeed in remediating these misinterpretations, leading to the present study in which two teaching methods are tested: refutational text and multiple external representations (MERs). Refutational text explicitly refutes an incorrect conception and provides an alternative, correct conception. MERs combine various external representations in order to improve the interpretation or understanding. These teaching methods were not only used separately, but also in combination. A posttest showed that students in the control condition scored weakest, and students in the combination condition scored best. The students in the MERs and refutational text conditions scored in between. The implications of these results for theory and educational practice are discussed.