How reliable are lifeguard visual search studies?

RESEARCH DIGEST 

How reliable are visual search studies?

Visual search studies need to be read with a degree of caution. Early work exploring the visual limitations in lifeguarding (Lanagan-Leitzel, 2012; Lanagan-Leitzel and Moore, 2010) used stimuli that consisted of videotaped swimming venues. Lifeguard participants looked at a few critical events (Lanagan-Leitzel and Moore, 2010), most likely because there is considerable variability in which events are reported by lifeguards to be critical (Lanagan-Leitzel, 2012). Szpilman et al. (2017) identified 64 variables that can influence the process of a single rescue, resulting in challenges for experimental design in lifeguarded settings. 

Lifeguard surveillance is not the same as static visual search (Lanagan-Leitzel, Skow, and Moore, 2015). Although video-based studies mimic real-life gaze behaviour (Underwood, Crundall, and Chapman, 2011), gaze behaviour in laboratories has often been shown to differ from gaze behaviour in situ (Dicks, Button, & Davids, 2010; Foulsham, Walker, & Kingstone, 2011; Zeuwts, Debuyck, Vansteenkiste, & Lenoir, 2013).

Despite the increased realism of the footage used, footage viewed on a laptop does not accurately replicate the visual search patterns and decision-making processes used in real-life scenarios. Laxton and Crundall (2018) critiqued the lack of realistic stimuli used in this area of research. 

Why is more research into visual search needed?

There is a growing body of contradictory evidence suggesting that visual search strategies do not materially improve detection rates among lifeguards. Future research should seek to understand the individual variability within organic search strategies and where knowledge reinforcement can be used to improve detection rates (Page et al., 2011). It is particularly important that additional longitudinal studies are conducted to assess the effectiveness of new interventions. 

Further research on how individual factors such as variability in emotional regulation and executive function affect lifeguard performance and whether established interventions in those domains translate benefits to lifeguarding detection rates.

Research into the mechanics of how lifeguards detect incidents over the last two decades has led to few successful intervention strategies. Whilst the mechanics of detection have attracted substantial academic interest, and the aquatics industry has been left to develop its own interventions to improve outcomes. A focus on field testing interventions already in existence over the next decade is needed. Reverse-engineering successful interventions could lead to improved knowledge of the mechanics of lifeguard detection. 

References

^{Dicks, M., Button, C. and Davids, K. (2010). Examination of gaze behaviours under in situ and video simulation task constraints reveals differences in information pickup for perception and action. Attention Perception and Phsychophysics. 72(3), 706-720.}  

^{Foulsham, T., Walker, E. and Kingstone, A. (2011). The where, what and when of gaze allocation in the lab and the natural environment. Vision Research. 51, 1920-1931.}  

^{Lanagan-Leitzel, L. K. (2012). Identification of critical events by lifeguards, instructors, and non-lifeguards. International Journal of Aquatic Research and Education. 6(3), 203-214. [A live, recorded video study of ten lifeguard instructors, twelve newly qualified lifeguards, seventeen lifeguards with experience an average experience of 2.5 years, and twenty non-lifeguards. Participants watched four, two-minute videos from each of the five ocean, lake and pool locations].}   

^{Lanagan-Leitzel, L., and Moore, C. (2010). Do lifeguards monitor the events they should? International Journal of Aquatic Research and Education. 4(3), 241-256. [A recorded simulation study involving ten primarily pool lifeguards of one and seven years experience and twenty non-lifeguards watched sixty, thirty-second video clips].}   

^{Lanagan-leitzel, L., Skow, E., and Moore, C. (2015). Great expectations: Perceptual challenges of visual surveillance in lifeguarding. Applied Cognitive Psychology. 29, 425–435}  

^{Laxton, V., and Crundall, D. (2018). The effect of lifeguard experience upon the detection of drowning victims in a realistic dynamic visual search task. Applied Cognitive Psychology. 32(1), 14-23. [An eye-tracking live video playback study of twenty-one UK lifeguards and twenty-one non-lifeguards observation of 45 video clips involving 3, 6 and 9 swimmers in an indoor pool].}   

^{Page, J., Bates, V., Long, G., Dawes, P., and Tipton, M. (2011). Beach lifeguards: Visual search patterns, detection rates and the influence of experience. Ophthalmic and Physiological Optics. 31(3), 216 –224. [A recorded simulation study involving beach lifeguards and non-lifeguards].}   

^{Szpilman, D., Doyle, B., Smith, J., Griffiths, R., & Tipton, M. (2017). Challenges and feasibility of applying reasoning and decision making for a lifeguard undertaking a rescue. International Journal of Emergency Mental Health and Human Resilience. 9,1-9.}   

^{Underwood, G., Crundall, D., and Chapman, P. (2011). Driving simulator validation with hazard perception. Transportation Research Part F. 14, 435-446.}  

^{Zeuwts, L., Debuyck, G., Vansteenkiste, P., and Lenoir, M. (2013). Is there a difference in visual search patterns between watching video clips of fencers on a computer screen and reacting on them on a life-size screen? Proceedings of the 2013 conference on eye tracking South Africa. 1.}  

Citation: Jacklin, D. 2021. How reliable are lifeguard visual search studies? Water Incident Research Hub, 29 December.