Abstract

This study explored the accuracy and certainty of 20 umpires and 20 nonumpires who provided judgments about a tactile discrimination task, made calls for videotaped pitches, and rated their certainty for both tasks. There were no differences in accuracy or certainty between the groups on either task. However, on the baseball task accuracy accounted for only 32 of the variability in certainty for umpires while it accounted for 69 of the variability in certainty for nonumpires. These reults suggest that umpires do not report high certainty about all judgements, but that they may overrepresent their certainty for officiating tasks. Results also provide further confirmation of the observation that umpires have reduced the size of the strike zone. Investigators discuss other extraneous social variables that may influence the performance of baseball umpires. Verf.-Referat