Location Dependent Fixation Analysis with Sight Vectors. Locomotion as a Challenge in Mobile Eye Tracking

Mobile eye tracking has become a fruitful method for spatial research. Body movement and orientation as well as the complexity of real-­‐world surround-­‐ ings have a strong influence on the processing of environmental information that can be captured by mobile eye tracking devices. On a methodological level, perceiv-­‐ er locomotion is both a challenge due to the complexity of the data, as well as a val-­‐ uable resource of information. In this paper we propose a new approach to inte-­‐ grate observer location information and fixation data using sight vectors. This meth-­‐ od is a crucial step towards furthering the analysis of mobile eye tracking data and the understanding of the perception of moving observers in complex environments. Keywords: Mobile Eye Tracking, Situated Cognition, Locomotion, Sight Vectors, Visuospatial Perspective. 1 Mobile Eye Tracking during Locomotion In the last years mobile eye tracking has become a popular method of veering away from studies in the laboratory and investigating eye movements in real environments. This move is important insofar as it is yet unclear to what extent the results obtained from eye tracking studies in the lab bear external validity so that conclusions drawn from them can be transferred to the real world [1, 2]. However, using mobile eye tracking poses new challenges for data analysis, in particular in spatial tasks where persons can move freely through a complex environment. Both the complexity of the environment as well as the movement of the observer are, on the one hand, aspects that can hardly be accounted for in lab studies, but, on the other hand, make it necesET4S 2014, September 23, 2014, Vienna, Austria Copyright © 2014 for the individual papers by the papers' authors. Copying permitted for private and academic purposes. This volume is published and copyrighted by its editors. ET4S 2014