Interactive TV user interfaces: how fast is too fast?
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The analysis presented in this paper is the search for optimal scrolling speeds of the user interface for interactive TV (iTV) navigation. The most popular navigation techniques for browsing through user interfaces usually incorporate scrolling. Furthermore, the latest set-top-boxes have enough processing power to support very fast scrolling, not only for texts, but also for photographs and other elements. We designed and performed an experiment to measure the optimal scrolling speed for different activities on a user interface. We found that the optimal speed depends on the type and complexity of the navigational elements (like text or graphics). We discovered that less-complex elements, such as numbered TV-channel names, tolerate much higher scrolling speeds than more-complex elements, such as graphical elements like movie posters. We also analyzed the impact of the direction of navigation (vertical, horizontal) on the optimal speeds and the results show no major impact on the graphical elements, while for the text elements the difference is obvious. The results of this study can improve the usability of the horizontal and vertical navigation techniques in modern iTV navigation.
KeywordsUser interface Navigation Scrolling Speed Interactive TV
The authors would like to thank Gregor Fuis and Sergej Eržen for their help with the testing-environment preparation and all the participants who took part in the evaluation study. The research work was partly performed in the scope of research program P2-0246—Algorithms and optimization procedures in telecommunications, financed by the Slovenian Research Agency.
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