Modeling and predicting pointing errors in two dimensions

Recently, Wobbrock et al. (2008) derived a predictive model of pointing accuracy to complement Fitts’ law’s predictive model of pointing speed. However, their model was based on one-dimensional (1-D) horizontal movement, while applications of such a model require two dimensions (2-D). In this paper, the pointing error model is investigated for 2-D pointing in a study of 21 participants performing a time-matching task on the ISO 9241-9 ring-of-circles layout. Results show that the pointing error model holds well in 2-D. If univariate endpoint deviation (SDx) is used, regressing on N=72 observed vs. predicted error rate points yields R2 =.953. If bivariate endpoint deviation (SDx,y) is used, regression yields R2 =.936. For both univariate and bivariate models, the magnitudes of observed and predicted error rates are comparable.

• Type: Journal
• Year: 2011
• Where: CHI
• Authors: Jacob O. Wobbrock, Alex Jansen, Kristen Shinohara
• Keywords: CHI 2011, Error Model, Horizontal Movement, Human Computer Interaction, Predictive Model