Employing Shortcut Setting and Subitizing Effect for Improving UI of Multi Media Kiosks

Abstract

Convenience stores are almost everywhere, offering a modern part of life. Convenience stores in Taiwan also serve as links to the world where you can pay gas bill or even get tickets for a concert through the self-service Multi Media Kiosks (MMK). Self-service Multi Media Kiosks (MMK) were set up by domestic convenience stores (i-bon, FamiPort, Life-ET, OK·go) in Taiwan, offering on line services like payment, value-adding, ticket booking and others. Nevertheless, with more and more services provided through MMK, too many options in the main menu often confuse users and usability problems arise. Shortcuts enables users quickly start common or recommended tasks within MMK’s main menu. One of the effort to improve the problem in main menu is to define shortcuts to specific actions according to prevailing tasks among users. Unfortunately, the pilot study remarked that half of the users didn’t notice the presence of accessible shortcut options. For this reason, this study intended to validate effectiveness of shortcuts setting and assume that page layout and number of selection keys are essential to user’s visual search efficiency. To achieve the goal, an innovative MMK’s main menu prototype was developed by adapting the layout and option features following visual search theories of subitizing effect that suggest a clear limit in the accuracy of numerosity judgements was found to be set at 4. Limit number of allowed selections in one page did challenge the hierarchical structures of MMK’s content management but was worth trying. In the proposed prototype, eight recommended shortcut options were set quaternary groups in the first page of MMK user interface, followed by (responsively disclosed) content of main menu, in which, quaternary groups layout was employed again. The usability evaluation of proposed prototype was completed by users experiment. Research findings include: (1) For those participants aiming to reach the prevailing tasks, the utility rate of enhanced features shortcut options was promoted to 100%. (2) For those participants aiming to reach the non-prevailing tasks, although having to go through shortcut options page and then shift to main menu, the average operation time is not slower than that of two existing MMK systems with lower error rate. The result indicated that subitizing effect works!