In foul decision-making by football referees, visual search is important for gathering task-specific information to determine whether a foul has occurred. Yet, little is known about the visual search behaviours underpinning excellent on-field decisions. The aim of this study was to examine the on-field visual search behaviour of elite and sub-elite football referees when calling a foul during a match. In doing so, we have also compared the accuracy and gaze behaviour for correct and incorrect calls. Elite and sub-elite referees (elite: N = 5, Mage ± SD = 29.8 ± 4.7yrs, Mexperience ± SD = 14.8 ± 3.7yrs; sub-elite: N = 9, Mage ± SD = 23.1 ± 1.6yrs, Mexperience ± SD = 8.4 ± 1.8yrs) officiated an actual football game while wearing a mobile eye-tracker, with on-field visual search behaviour compared between skill levels when calling a foul (Nelite = 66; Nsub−elite = 92). Results revealed that elite referees relied on a higher search rate (more fixations of shorter duration) compared to sub-elites, but with no differences in where they allocated their gaze, indicating that elites searched faster but did not necessarily direct gaze towards different locations. Correct decisions were associated with higher gaze entropy (i.e. less structure). In relying on more structured gaze patterns when making incorrect decisions, referees may fail to pick-up information specific to the foul situation. Referee development programmes might benefit by challenging the speed of information pickup but by avoiding pre-determined gaze patterns to improve the interpretation of fouls and increase the decision-making performance of referees.
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Numerous laboratory-based studies recorded eye movements in participants with varying expertise when watching video projections in the lab. Although research in the lab offers the advantage of internal validity, reliability and ethical considerations, ecological validity is often questionable. Therefore the current study compared visual search in 13 adult cyclists, when cycling a real bicycle path and while watching a film clip of the same road. Dwell time towards five Areas of Interest (AOIs) is analysed. Dwell time (%) in the lab and real-life was comparable only for the low quality bicycle path. Both in real-life and the lab, gaze is predominantly driven towards the road. Since gaze behaviour in the lab and real-life tends to be comparable with increasing task-complexity (road quality), it is concluded that under certain task constraints laboratory experiments making use of video clips might provide valuable information regarding gaze behaviour in real-life.
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In this study, we examined the effects of a defender contesting jump shots on performance and gaze behaviors of basketball players taking jump shots. Thirteen skilled youth basketball players performed 48 shots from about 5 m from the basket; 24 uncontested and 24 contested. The participants wore mobile eye tracking glasses to measure their gaze behavior. As expected, an approaching defender trying to contest the shot led to significant changes in movement execution and gaze behavior including shorter shot execution time, longer jump time, longer ball flight time, later final fixation onset, and longer fixation on the defender. Overall, no effects were found for shooting accuracy. However, the effects on shot accuracy were not similar for all participants: six participants showed worse performance and six participants showed better performance in the contested compared to the uncontested condition. These changes in performance were accompanied by differences in gaze behavior. The participants with worse performance showed shorter absolute and relative final fixation duration and a tendency for an earlier final fixation offset in the contested condition compared to the uncontested condition, whereas gaze behavior of the participants with better performance for contested shots was relatively unaffected. The results confirm that a defender contesting the shot is a relevant constraint for basketball shooting suggesting that representative training designs should also include contested shots, and more generally other constraints that are representative of the actual performance setting such as time or mental pressure.
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Measuring and designing user experience in retail and gaming virtual reality using a CAVE set-up In this project we designed and measured user experiences in a CAVE virtual reality set-up. Virtually all studies have taken the form of experiment studies and have been conducted among consumers (in total more than 1500 consumers) who had to visit the virtual world with assignments based on which behaviour has been observed and after which a survey was conducted afterwards. The studies were carried out within the three lines of inquiry: a. Branded games / in-game advertising, revealing (positive) effects of in-game advertising on attention and attitude based on logos and faces incorporated into the games. Various applications (prototypes) have been developed that stimulate the shopping experience and the interaction between shop and consumer. (b) FMCG: studies answered the question which factors influence search and choice behaviour in the supermarket. On the basis of the studies, the clients have designed new packaging and adapted existing designs, deployed new shelf layouts, developed and implemented new Retail strategies, optimized instore communication and (e) the knowledge about consumer behaviour in the supermarket within the organization has been increased. (c) Location Based Advertising: recommendations have been made for the partners concerned and the field of work on (a) development of non-intrusive pervasive/ubiquitous advertising concepts (2nd screen, LBA, gaze-based advertising etc.), (b) development of virtual test environments and associated interaction methods and (c) exploration and review of theoretical models for persuasive communication and behavioural influence. Partners: Heinz, Nokia, DVJ-Insights, Radboud University, Brand Loyalty, IRI, Talpa, TU/e, Philips