Paper on small-screen usability 26Aug05

At PMN Marek Pawlowski linked to a paper on small-screen usability:

"The small screen sizes of mobile phones can create problems for users. There is a need for acceptable user interfaces that enable a better, more maximised use of the limited screen size while still providing high levels of usability. One method of maximising a limited display area is translucency. To examine the effect of translucency on interface usability we created a fully functioning simulation of a third generation mobile phone user interface, containing a translucent menu system. In this study translucency was implemented at 50% alpha, and two menu levels deep. Objective and subjective aspects of usability and acceptance were gathered. Within the focus of the research the study yielded interesting findings positively relating translucency to perceived usability and measures of acceptance of small screen information systems. This paper presents the results of this study, and presents avenues for continuing research arising from the findings.
(...)
The study yielded interesting results. On a subjective level the presence of translucent menus had very substantial effects: the translucent interface was perceived to be more enjoyable and more attractive than the control version. Additionally for the translucent interface, navigation through nested menus was found to be easier, and the presence of translucency perceived to be useful. Yet the objective measures showed no real differences in terms of the time taken to complete tasks, or the number of errors made, between the translucent and non-translucent systems. Thus, from an objective viewpoint translucent menus did not enable users to complete tasks more quickly, or with fewer errors, yet subjectively translucency gave users the “feeling” of having a more usable interface. As a result of this discrepancy we further investigated the inter-connectedness between perceptions of ease-of-use, enjoyment, attractiveness, and usefulness. In so doing we found that user perceptions of the interface as enjoyable led directly to a higher perception of how easy it is to use. In addition, perceiving the translucent menu version to be more attractive led directly to an
increased perception of its usefulness.
The key finding here is that user perceptions directly influence the usability rating achieved by a system’s user interface. Such perceptions can be based on subjective items such as the extent to which the user interface is attractive and enjoyable, rather than on objective measures such as task completion times. This particular study, at the solitary 50% translucency level implemented, shows that although translucent menus did not speed up or slow down user interactions with their mobile phone, designers may wish to include translucent menu systems in small-screen systems to increase enjoyment and attractiveness, as a means of achieving a better usability rating by users."

Internetverweis

PDF - “Usability and Acceptance in Small-Screen Information Systems.” (via pmn)
PNM - Paper on small-screen usability