Concept evaluation and usability testing of a TV based video communications system

Attempts to successfully commercialize video telephony have thus far failed, however technical developments in broadband networks, video encoding, imaging and processing are now making TV based video telephony both technically and commercially viable. This paper describes two empirical studies carried out to evaluate such a concept. A first study assessed the user value of TV based video telephony by means of a comparative evaluation against a PC/webcam solution and face to face communication using subject dyads and structured audio/visual tasks. Significant differences were found between all three conditions; while pre- and post-test Likert scales indicated that ratings for the TV condition increased post-experience and were not significantly different from the face to face condition ratings. Two prototype systems were then developed which enabled TV to TV video telephony calls and a second study was carried out to evaluate in greater depth, the usability and acceptability of the feature sets and their respective ease of access. The studies indicated that TV-based video communications does have intrinsic user value and also has the potential to approach the richness of face to face communications, but that certain control and privacy functions need to be implemented in the UI before this can be fully realized. Such functions included; control over the callers with whom video would be used, control over who could access the videotelephony system, control over the recording of calls, the ability to turn off the self-view and, for total privacy, physical occlusion of the camera when not in use.

► We report two studies evaluating a prototype videotelephony system. ► A comparative concept study of TV based communications with webcam & face-to-face. ► A usability study of two prototype UIs. ► Results indicate positive user value but privacy & security concerns found. ► Recommendations provided for addressing user security issues.