Assessing the validity and reliability of a baseball pitch discrimination online task

Abstract

There has been an increasing interest in training perceptual skills in sports through online video-based methods, particularly in baseball. However, there is little empirical evidence related to the reliability and validity of such online methods for the assessment of these skill. Here we developed an online task to assess pitch discrimination and evaluated (a) inter-item reliability, (b) reliability in assessment compared to an in-person task, also tapping into external validity and (c) discriminability across different skill groups. We also compared performance on a non-sport specific Dynamic Visual Acuity task (DVA), thought to tap into underlying visual skills comprising pitch discrimination. Skilled, Varsity-level baseball players (n = 17) were compared to novices (n = 14) when discriminating pitches thrown by two different pitchers, across three pitch types, edited to progressively remove sections of ball flight (3 time points). The online task discriminated across skill groups, showed good reliability across repeated viewings and from the online task to an in-person assessment of skilled athletes (n = 8). There were, however, differences in reliability and discriminant validity based on the type of pitcher, with one pitcher being responded to more accurately and reliably. Skilled participants showed good discriminability between fastballs and change-ups. There were no group differences for DVA, nor did it correlate with pitch discrimination for the skilled group. These data illustrate the reliability of online video assessments, but raise issues concerning discriminability across different pitchers and when standing ready to swing. Greater sensitivity testing of such assessments is still needed, within and across skill groups.