Publication

Eye movements when using a mobile phone to search on wall maps

Robert Schleicher; Michael Rohs; Johannes Schöning

In: ECEM 2009: Proceedings of the 15th European Conference on Eye Movements. European Conference on Eye Movements (ECEM-09), August 23-27, Southampton, United Kingdom, 2009.

Abstract

We report an experiment where subjects had to find hotels on wall maps using a camera phone. When moved over an item, its display showed the camera view plus additional information that was not available on the wall maps, but necessary for selection. Trials varied with regard to number of items and different ways to mark a hotel with the phone. Eye movements were recorded binocularly with a head-mounted Eyelink II eyetracker. We used differences in x- coordinates of left and right eye to determine the plane the subjects looked at, i.e. phone display or wall. In all conditions, average search time, fixation duration and baseline-corrected pupil size increased with item set size indicating higher difficulty and mental workload. 'Good' searchers with less than 5 percent error trials solved the task faster and showed significantly more gaze shifts between mobile display and wall map per minute than 'bad' searchers with more than 10 percent error trials. The difference between these groups in frequency of errors as well as mean fixation time became more pronounced with increasing set size. We therefore conclude that this way of interaction with wall maps is best suited for tasks which involve a low number of items.