oldenburg.de

oldenburg.de Touchscreens became the dominant input device for smartphones. Users ’ touch behaviour has been widely studied in lab studies with a relative low number of participants. In contrast, we published a game in the Android Market that records the touch behaviour when executing a controlled task to collect large amounts of touch events. Players ’ task is to simply touch circles appearing on the screen. Data from 91,731 installations has been collected and players produced 120,626,225 touch events. We determined the error rates for dif-ferent target sizes and screen locations. The amount of data enabled us to show that touch positions are systematically skewed. A compensation function that shifts the users ’ touches to reduce the amount of errors is derived from the data and evaluated by publishing an update of the game. The independent-measures experi-ment with data from 12,201 installations and 15,326,444 touch events shows that the function reduces the error rate by 7.79%. We argue that such a compensation func-tion could improve the touch performance of virtually every smartphone user. ACM Classification Keyword