“…This is in stark contrast to remote eye tracking, where several studies have called attention to the characterization of eye-tracking data quality (Blignaut & Wium 2014;Wass, Forssman, & Leppänen, 2014;Nyström, Andersson, Holmqvist, & van de Weijer, 2013;Hessels, Andersson, Hooge, Nyström, & Kemner, 2015), with some studies specifically examining data quality using a series of tests mimicking participant behavior during typical recording sessions (Hessels, Cornelissen, Kemner, & Hooge, 2015;Niehorster, Cornelissen, Holmqvist, Hooge, & Hessels, 2018). Although it has been established that eye camera positioning and illumination conditions can greatly influence tracking quality in head-worn eye tracking (Świrski, Bülling, & Dodgson, 2012;Tonsen, Zhang, Sugano, & Bülling, 2016;Fuhl, Tonsen, Bülling, & Kasneci, 2016), to the best of the authors' knowledge, only a single study has actually empirically compared the accuracy and precision of multiple head-worn eyetracking setups-yet the study (MacInnes, Iqbal, Pearson, & Johnson, 2018) was limited in scope to the ideal case of careful calibration and evaluation immediately thereafter. It is therefore not representative of how these eye-tracking setups are often used with unconstrained participants in uncontrolled environments.…”