(In)Accuracy of Human-Generated Correlations in A Scatterplot Drawing Task
Abstract
Previous research on perception of correlation of scatterplots used scatterplots as stimuli and asked participants to estimate or compare correlations of those scatterplots. This literature has shown a tendency for people to underestimate correlation in some correlation ranges. We flipped the task: instead of estimating correlation from visual stimuli, participants drew a scatterplot based on a given correlation: 0, 0.25, 0.5, 0.75 and 1 using 20 dots. Participants drew greater correlations for r = 0.25 and r = 0.5 (0.59 and 0.71 respectively), which is analogous to underestimating correlation in previous viewing tasks. Drawn correlations for r = 0, 0.75 and 1 were more accurate. The number of statistics courses taken did not improve correlation drawing accuracy in a strong or meaningful way. We discuss possible interpretations of these results and future directions.