A User Study with GUIs Tailored for Smartphones and Tablet PCs

Usually, Web-based graphical user interfaces (GUIs) are not specifically tailored for different devices with touch-screens, such as smartphones and tablet PCs, where interaction is affected mainly by screen size. There is little scientific evidence on the conditions under which additional taps for navigation are better than scrolling or vice versa. Therefore, we conducted a user study in which we experimentally evaluated GUIs tailored for a smartphone and a tablet PC, respectively. Each participant performed the same task with two different layouts of the same GUI, either on a given smartphone or tablet PC. We collected quantitative data through measuring task completion time and error rates, as well as qualitative data through subjective questionnaires. The main result is that tailoring a GUI specifically for a smartphone or tablet PC, respectively, is important, since screen size matters. Users performed significantly better when they could use the tailored version on the given device. This preference was also reflected in their subjective opinions.