Touch Interfaces from a Usability Perspective : Effective Information Presentation for User Interaction on a Touch Screen

Abstract: Decerno is a software consultancy company who designs and builds large software information systems. They are interested in more knowledge and insight in the benefits and limitations of touch-enabled interfaces as a means of incorporating these into their own products. The aim of this study is to find advice on how to design touch-enabled functionality that would work in a company’s main computer system to be used by staff on a daily basis in order to fulfill their work tasks.Comparing a touch interface to a conventional mouse interface exposes differences in use that need to be kept in mind when designing for touch interaction usability. With a simple flick of the mouse you are able to dart your mouse-pointer across the screen on your conventional mouse interface, but a touch interface requires you to both lift and extend your arm in order to point your finger at the far corner of the touch screen. Extensive use of large or monotonous movements might cause muscle fatigue, which requires you to adapt your interface design to allow for effective touch-interaction use.The main research question in this study has been to derive guidelines and advice on how to present a set of dynamic information making it possible for the user to effectively find and select a specific target by touch interaction. For this purpose a set of sub questions were identified and a test interface was produced in order to evaluate the users touch interaction and their feedback. The results from these user tests have formed the foundation of the concluding guidelines.This has been evaluated both quantitatively and qualitatively in a user study. Measurements was taken on how the users performed, such as number of errors and time to finish the user task. The users were also asked to perform a think-aloud evaluation which collected information on how they used the interface and their thoughts and reactions while doing it. The user tests were concluded with open-ended questions in which the users were asked to reflect on their actions, how user-effective the interface was and to compare different test setups.The results conclude that most users does not like horizontal scrolling. The horizontal movement make the text much harder to follow. Habit also seems to be an important factor as several users expressed the fact that they are much more used to scrolling vertically.Most users preferred the display with both images and text as it made the page more interesting and pleasant to look at, this is in contrast with the fact that most users stated that locating an item is faster and easier without images and only minimal text information, limited to only the search task answer. The aesthetical features of an interface seem to be equally important as the functionality.Another important conclusion is the difference in hand-position when the tablet is placed on the table compared to when it is hand-held. When designing a touch interface, some consideration should be taken to how the user might be working with the interface. The button placement might need to be different depending on if they are likely to be holding the tablet while using it (perhaps in a more informal setting, standing up or moving around) or will they be using it while it is placed on the table.