Cross-Modal Equivalence of Visual and Auditory Scatterplots for Exploring Bivariate Data Samples

The equivalence of visual and auditory scatterplots was examined in two experiments. Experiment 1 examined the relationship between actual Pearson's r and visual and auditory judgments of direction and magnitude of correlation for 24 bivariate data samples. Experiment 2 directly evaluated visual and auditory perceptual sensitivity to outliers by examining changes in perceived magnitude and direction of correlation estimates for scatterplots from Experiment 1 that were altered by the addition of outlier points. Results suggest that the information conveyed by visual and auditory scatterplots is used very similarly by the two modalities. Both visual and auditory scatterplots are quite efficient in conveying sign and magnitude of correlation, and the effect of outliers on judged magnitude of correlation is similar for the two types of data display.