title: Visual scan patterns and decision-making skills of expert assistant referees in offside situations.
abstract: The offside decision-making process of international and national assistant referees (ARs) was evaluated using video simulations. A Tobii T120 Eye Tracker was used to record the eye movements. Two hypotheses for explaining incorrect decisions were investigated, namely, the flash-lag effect and the shift of gaze. Performance differences between skill levels were also examined. First, results showed a bias toward flag errors for national ARs as expected by the flash-lag effect. Second, ARs fixated the offside line before, during, and after the precise moment the pass was given, implying there was no shift of gaze from the passer to the receiving attacker. Third, no differences were found in scan patterns between international and national ARs. In conclusion, international ARs seem to have found a strategy to better deal with the perceptual illusion resulting from the flash-lag effect. Based on their experience, they have learned to correct for this illusion, and, consequently, show fewer flag errors.
authors.affiliation: Laboratory of Perception and Performance, Research Center for Movement Control and Neuroplasticity, Department of Biomedical Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Heverlee, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Catteeuw
authors.forename: Werner
authors.initials: W
authors.lastname: Helsen
authors.forename: Bart
authors.initials: B
authors.lastname: Gilis
authors.forename: Evelien
authors.initials: E
authors.lastname: Van Roie
authors.forename: Johan
authors.initials: J
authors.lastname: Wagemans
mesh_terms: D000328:Adult; D001530:Belgium; D003198:Computer Simulation; D003657:Decision Making; D005133:Eye Movements; D005403:Fixation, Ocular; D006801:Humans; D007088:Illusions; D011361:Professional Competence; D017603:Signal Detection, Psychological; D012916:Soccer / Q000523:psychology*