In addition, gaze behaviour depends on the task: when judging a foul, the referee uses different eye and head movements than when assessing the direction of a long pass. This is shown in research by movement scientist Tammie van Biemen of VU Amsterdam.
What does a referee look at when making decisions on the football pitch? Movement scientist Tammie van Biemen studied the gaze behaviour of football referees. ‘For my research, I had professional and amateur referees officiate a (practice) match while wearing special camera glasses,’ says Van Biemen. These matches were specially organised for this study, with conditions exactly the same as normal matches. ‘Professional referees officiated matches with teams from professional football and amateur referees officiated teams from the Derde Divisie, Vierde Divisie and Eerste Klasse, so the level of the games matched the level of the referees,’ Van Biemen says.
Inside the special camera glasses that the referees wore during these matches were several cameras: one that filmed the surroundings just like a normal camera and two cameras that filmed the eyes. Van Biemen: ‘By basically superimposing those images, you can see exactly what someone is looking at.’
The gaze behaviour of professional referees was compared with that of amateurs. ‘This allowed me to see if there are differences and if there is ‘ideal’ gaze behaviour. You could then potentially use that to train referees’, explains the movement scientist.
Van Biemen concludes, among other things, that referees adapt their gaze behaviour to the situation. ‘When a referee has to judge a foul, he uses different eye and head movements than when he has to judge the direction of a long pass.’
In addition, the level of the referee influences their gaze behaviour. Van Biemen: ‘For example, professional referees look faster at fouls than amateurs. In addition, top referees do not show one specific type of eye gaze behaviour, but have the skill to adapt to the situation.’ Not all top-level referees show the same behaviour; individual preferences also play a role. ‘Some professional referees have a very active search strategy in open game situations, with lots of head and eye movements, while other professional referees use a more passive strategy,’ van Biemen explains. ‘It is therefore important to examine gaze behaviour not only at the group level but also at the individual level.’
Lastly, it turns out that a virtual reality environment can mimic gaze behaviour on the field very well while watching video images leads to very different behaviour. Important information if you want to train gaze behaviour. This is why Van Biemen recommends investing in virtual reality (VR). ‘VR can be a representational environment in which behaviour can be taught and practised and thus contribute to developing skills for referees,’ Van Biemen says. ‘In addition, VR can also help recruit new referees and create awareness and respect for referees. These applications make VR a valuable investment for referee training programmes. And last but not least, referees also find it a lot of fun!’
Van Biemen works as a referee development advisor at the Royal Dutch Football Association (KNVB), where she focuses on data and innovation. ‘I try to make more and better use of data in our work processes, for example, for handling match appointments, assessing referees’ performance or training new referees,' says Van Biemen. She also puts her research into gaze behaviour into practice, for example by exploring the possibilities of using VR, but also by implementing opportunities to train communication in matches. ‘The KNVB is interested in referee communication and because the camera glasses record not only images but also sound, this gave a unique insight into the verbal communication referees use.’