Exploring callout design in selection task for ultra-small touch screen devices
Akira Ishii, Buntarou Shizuki · 2016
Ultra-small touch screen devices tend to suffer from occlusion or the fat finger problem owing to their limited input area. A callout could solve these problems by displaying a copy of the occluded area in a non-occluded area. However, callout designs for ultra-small touch screen devices have not yet been explored in depth. In this study, we chose three design factors (each factor has two levels) from various factors and conducted an experiment to examine eight callout designs in the selection task for ultra-small touch screen devices. The results of our experiment matched the results from previous research; however, we also obtained results unique to ultra-small devices. The results showed that the selection speed was higher when the content of the callout was changed continuously, the error rate decreased when the content of the callout was changed continuously and a pointer was displayed to indicate the touched position within the callout, and the workload decreased when the content was changed continuously. Further, as a design factor, the position of the callout would not affect the selection performance.