Task-based evaluation of meeting browsers: from BET task elicitation to user behavior analysis

This paper presents recent results of the application of the task-based Browser Evaluation Test (BET) to meeting browsers, that is, interfaces to multimodal databases of meeting recordings. The tasks were defined by browser-neutral BET observers. Two groups of human subjects used the Transcript-based Query and Browsing interface (TQB), and attempted to solve as many BET tasks – pairs of true/false statements to disambiguate – as possible in a fixed amount of time. Their performance was measured in terms of precision and speed. Results indicate that the browser’s annotation-based search functionality is frequently used, in particular the keyword search. A more detailed analysis of each test question for each participant confirms that despite considerable variation across strategies, the use of queries is correlated to successful performance.