Place Metaphor in Digital Television

We report findings from two usability studies of digital television (DTV). A preliminary study was undertaken with eight subjects. The final study had thirty subjects. It was found that content and interface elements should be evaluated in terms of concrete and conceptual nearness with respect to all parts of the DTV experience. Additionally, several features of the DTV application interface were salient in user evaluations: navigation and structure, choice of content, level of engagement, interface display and timing, responsiveness, and multimedia design. Definitions In this paper a Digital Television Package (DTP) is seen as consisting of three parts: the Digital Television Equipment (DTE) which includes a remote control and a set-top box, the Digital-TV show (DTV show), and the Digital-TV Application (DTA), e.g., an interactive service or a set of services for use with a DTV show. The DTA is in turn composed of content (DTA content) and a user interface (DTA interface) through which the content is accessed. The DTA is implemented by programmers using a DTA Software Development Kit (SDK). Lastly a DTP can be said to be in one of two states: TV mode or interface mode. On the one hand, if a subject is watching a TV show, then this person is using the DTP in TV mode. On the other hand, if the subject is interacting with the DTA interface then the subject is using the DTP in interface mode. These defined terms can also be found in the glossary at the end of this paper. Introduction DTV use remains scarce in Sweden despite governmental and commercial efforts to market the technology. There are many possible reasons for why the DTV-adoption rate is low. From the developers’ perspective, the design constraints imposed by available DTA SDK:s and DTE:s severely limit the range of possible applications. DTV technology has simply not developed to a point of meeting neither the expectations of designers nor those of programmers. The situation is reminiscent of that which print-oriented design firms faced a few years ago when they were asked to design web sites. Art directors and web programmers became frustrated because many ideas could not be realized with suffient quality on the web. Now, DTV designers and programmers struggle with similarly difficult and limited technologies haunted by compatibility, flexibility and bandwidth issues (see the discussion section). Moreover, developers lack a solid foundation of literature and guidelines pertaining to digital television interface design. DTA designers often turn to design principles and metaphors from text-TV, the Internet (the web in particular) and multimedia at large for inspiration. Multimedia applications generally extend the basic desktop framework by providing refined methods of interaction, i.e., highlighting and sound cues (of course many recent desktopinterfaces are multimedia applications per se). At this point in the history of DTV it is still unclear, however, what interface styles works and under what circumstances. Other application areas of human-computer interaction are better researched with respect to interfaces. The world of personal computers, i.e., is dominated by direct manipulation [Schneiderman '82] desktop-style interfaces. Whether or not (depending on use conditions) the desktop-style interface is suited for DTA:s is a question open for debate. Many TV viewers have little or no experience with desktop-style interfaces (or PC:s for that matter). The research presented here hopes to make a contribution, partly by taking the interface style as an issue open for debate. The two explorative studies reported from here were undertaken to guide UR, a government funded educational broadcasting institution, in designing interfaces and applications for distance-learning DTV. Project management at UR realized that it’s experience with Swedish text-TV (similar to UK teletext) and analogue-TV programming was a good, but not optimal, base for constructing DTV interfaces and applications. In order to construct a better base for DTV-interface design, UR decided on conducting a series of usability studies.