Designing interfaces for multiple-goal environments: Experimental insights from in-vehicle speech interfaces
Designing computer-human interfaces for multiple-goal environments is challenging because people pursue multiple goals with conflicting priorities. Safety-critical environments, such as driving, aggravate the need for a more nuanced understanding of interfaces that may reconcile conflicting tasks. Speech interfaces are prime examples of such interfaces. In this article, we investigate how design variations of an in-vehicle speech interface influence performance of a primary task (driving safely) and a secondary task (e-mailing). In a controlled experiment, we test the performance implications of using single computer-generated Text-To-Speech (TTS) voice and multiple matching TTS voices while users respond to e-mails with varying levels of complexity during driving. Our results indicate that the number of voices used has a significant effect on both driving performance and handling e-mail--related activities. We discuss potentially unintended consequences of making the interface too naturalistic and too engaging for the driver and conclude with theoretical and practical implications.
Truschin, S., Schermann, M., Goswami, S., and Krcmar, H. (2014): ”Designing Interfaces for Multiple-Goal Environments: Experimental insights from In- Vehicle Speech Interfaces”, ACM Transactions on Computer-Human Interaction (21:1), Article 7.