Choosing a Dialogue System’s Modality in Order to Minimize User’s Workload

The communication during human-machine interaction often happens only as a secondary task that distract the user’s main focus on a primary task. In our study, the primary task was driving a vehicle and the secondary task was an interaction with a dialogue system on a tablet device using touch and speech. In this paper we present the design and the analysis of a study that can be used to create an optimal strategy for a dialogue manager that takes into consideration several metrics. These include the type of the information we require from the user, the expected cognitive load on the user, the expected duration of a user’s response and the expected error rate.