PURPOSE This study investigated how mental rotation ability affects diving referees’ judgment accuracy through two experiments. METHODS Experiment 1 involved 32 certified diving referees and examined the relations among their prior experience, mental rotation ability, and judging error. Experiment 2 randomly assigned nine novice referees to one of the following training conditions: (1) observational + mental rotation training (OMRT), (2) observational + imagery training (OIT), and (3) observational training only (OT). The effects of each intervention were assessed using a multiple baseline design. RESULTS Experiment 1 showed significantly reduced judging errors due to motor experience and object-centered mental rotation accuracy, whereas no significant effect was observed from refereeing and visual experience. Experiment 2 showed that the OMRT group had the greatest improvement in judgment accuracy and mental rotation performance, while the OIT group displayed moderate improvement, particularly in egocentric mental rotation. CONCLUSIONS Judges’ decision-making accuracy is closely linked to their mental rotation ability. Referee education programs that incorporate mental rotation and imagery training may significantly enhance judging precision and consistency in competitive diving.
