This paper presents a comparative study on the usability of a service presented in telephone, PC-based web interface, and mobile/ multi-modal variants. The goal is not to analyze individual strengths and weaknesses of the different modalities, but to understand the user's perception of the SUMI criteria (efficiency, affect/ likability, helpfulness, control, learnability), and the overall impression of a service with respect to the access variant tested. As multi-modality is often framed as a technology to make usage more "intuitive", we were particularly interested in the differences between experienced and novice users. To this end, we conducted a study with 80 participants and conclude that, while multi-modality is accepted by experienced users, it seems to be asking too much from novice users, particularly with respect to learnability and efficiency.
Bibliographic reference. Metze, Florian / Englert, Roman / Bub, Udo / Kliche, Ingmar / Scheerbarth, Thomas (2008): "User perception of multi-modal interfaces for mobile applications", In INTERSPEECH-2008, 2470-2473.