An Iterative Methodolgy to Improve TV Onscreen Keyboard Layout Design through Evaluation of User Studies

Certain applications (e.g web browsing, email etc.) in Television (TV) demand for text entry by the user in a similar fashion as done in computers. User experience plays a major role in the success of such applications. This paper discusses about an on-screen keyboard with hierarchical character or symbol organization which is operated by an accompanying remote control to allow navigation with reduced number of key strokes. The keyboard has been designed for Television and set top box users. It enhances user experience by allowing users to type easily and quickly. It also reduces cost by eliminating the need for a separate physical keyboard. This work has adopted iterative design cycles, where users' feedback arecollected and analysed in each cycle, and those have led to user-driven usability improvement. As the main contribution in this paper, we present a methodology for evaluating different on-screen keyboard layouts for television and set-top box users. In order to do this we have extended and applied KLM-GOMS model. Lastly we have incorporated predictive text entry technique with the proposed layout. We have extended the KLM-GOMS model further to include a new parameter called dynamic mental operator(DM) which takes into account the additional cognitive load on the users while using predictive text entry techniques.