A. Holzinger and K. Miesenberger (Eds.): USAB 2009, LNCS 5889, pp. 484–499, 2009. © Springer-Verlag Berlin Heidelberg 2009 Spoken Dialogue Interfaces: Integrating Usability Dimitris Spiliotopoulos, Pepi Stavropoulou, and Georgios Kouroupetroglou Department of Informatics and Telecommunications National and Kapodistrian University of Athens Panepistimiopolis, Ilisia, GR-15784, Athens, Greece {dspiliot,pepis,koupe}@di.uoa.gr Abstract. Usability is a fundamental requirement for natural language interfaces. Usability evaluation reflects the impact of the interface and the acceptance from the users. This work examines the potential of usability evaluation in terms of issues and methodologies for spoken dialogue interfaces along with the appropriate designer-needs analysis. It unfolds the perspective to the usability integration in the spoken language interface design lifecycle and provides a framework description for creating and testing usable content and applications for conversational interfaces. Main concerns include the problem identification of design issues for usability design and evaluation, the use of customer experience for the design of voice interfaces and dialogue, and the problems that arise from real-life deployment. Moreover it presents a real-life paradigm of a hands-on approach for applying usability methodologies in a spoken dialogue application environment to compare against a DTMF approach. Finally, the scope and interpretation of results from both the designer and the user standpoint of usability evaluation are discussed. Keywords: Speech, Spoken Dialog Interface, Usability, Usability Evaluation, Auditory User Interface, Human Computer Interaction, Accessibility, Computer Mediated Communication. 1 Introduction The late years’ research in communication, the world-wide-web and Human Computer Interaction (HCI) has led to significant advances in information access and revolutionized the way people exchange knowledge, learn and communicate. However, despite the newly designed approaches and technological advances, accessibility issues still constitute a barrier for a significant percentage of possible users, both mainstream as well as people with disability. People accessing the web or other educational material are usually presented with interfaces that, although make the information accessible; require either specific knowledge or expertise by the user. Moreover these are only designed as supplementary interfaces for use by special user groups in a specified modality or format as an alternative accessible means. Interfaces that are designed with only the accessibility as a solitary guide usually fail to present the real user with a usable means of communication.