Using language complexity to measure cognitive load for adaptive interaction design

An adaptive interaction system, which is aware of the users' current cognitive load, can change its response, presentation and interaction flow to improve users' experience and their task performance. In this paper, we propose a novel speech content analysis approach for measuring users' cognitive load, based on their language and dialogue complexity. We have analysed the transcribed speech of operators working in computerized incident control rooms and involved in highly complex bushfire management tasks in Australia. The resulting patterns of language complexity show significant differences between the speech from cognitively low load and high load tasks. We also discuss the value of using this approach of cognitive load measurement for user interface evaluation and interaction design improvement.