Visual search behaviours of association football referees

Referees' decisions are often a major talking point when it comes to sports games. With the need to make spilt second decisions that can influence the result, it's easy to see why. New research published today in Cognitive Research: Principles and Implications, a Springer Open journal (sister company of BioMed Central) looks at how top level referees' enhanced visual perception helps them spot foul play and make these split second decisions. Author of the study, Jochim Spitz, tells us more. You can also read this on the Springer Open blog

Referees are responsible for interpreting and enforcing the specific rules of a sport from a neutral point of view. The refereeing team deals with incidents over the entire field of play to maintain fair play and protect the players’ safety. Obviously, a referee’s decision might have an impact on the overall outcome of the game, for instance when a player is sent off or a goal is denied after a foul. As such, the performance of referees can have far-reaching consequences for players, clubs, fans, and other parties involved.

What makes an expert referee?

During a match, a referee has to make up his mind within a split second and take into account several sources of information. It is expected that, especially at the top level, referees make accurate, adequate and uniform decisions. This is an extremely demanding and difficult job with great responsibilities.

Over the past few years, extensive research has been undertaken with respect to the decision-making processes of players. The conclusion was that perceptual-cognitive expertise is a key factor in those sports where decisions have to be made under time pressure. This perceptual-cognitive expertise of players is reflected in their visual search strategy. Visual search behaviours of expert players are characterized by fewer and longer fixations on more informative areas of the visual display.

Few researchers, however, investigated the perceptual-cognitive demands and decision-making processes of referees. Referees don’t need to execute technically controlled motor actions, like players do, but the requirement to process information in an accurate and adequate manner may be deemed even more important.

The key sources of information for referees have never been determined and in our recent study, we used an eye tracker to examine the visual search strategies and the underlying decision-making processes of association football referees in more detail. By using such measures, we were able to identify the processes that mediate expert referees’ performance and also why certain situations can lead to incorrect decisions.

Focussing on crucial information

In our study, elite and sub-elite association football referees assessed foul play situations (open play and corner kick situations), filmed from an in-game perspective. Referees were seated in front of an eye-tracking monitor, allowing us to examine the exact location and duration of their fixations.

The elite referees made more accurate decisions compared to sub-elite referees and there were clear differences in their visual search behaviours. Elite referees spent significantly more time fixating the most informative areas (contact zones) and less time fixating the body parts and players that were not involved in the infringement (non-contact zones). As such, it seems that elite level referees have learned to discern relevant from irrelevant information in the same way as expert players.

Sub-elite referees tended to rely on less relevant information, spending longer periods of time fixating on the non-contact zones. Furthermore, all incorrect decisions were analysed in detail and it was concluded that, apart from visual attention, it is also important to give meaning to the perceived incidents and make a correct interpretation according to the Laws of the Game.

Perceptual-cognitive training of referees

A clear understanding of the way referees make decisions is crucial and our findings can be used to improve current training and coaching methods of referees. Nowadays, referee training is mainly focused on the physical preparation and key decision-making skills are only trained during real matches. Nevertheless, the number of officiated matches is rather low and new innovative training methods are required. An example of such an innovative training method is the online tool (, recently developed by KU Leuven in close cooperation with UEFA.

Several publications (e.g. Put et al., 2013) have demonstrated that this kind of video training, specifically developed to mimic the demands of the performance context, increases the accuracy of the decision-making process. Additional decision-making experience is offered in an accessible way and videos can be accompanied with appropriate (visual) feedback and specific instructions, resulting in more effective visual search strategies directed towards the crucial features of the display.

Jochim Spitz

Jochim Spitz is a PhD-student at KU Leuven, Movement control & Neuroplasticity Research Group. His doctoral project is funded by UEFA and focuses on expertise, decision-making skills and training of association football referees.

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