Usability of dialogue design strategies for automated surname capture

Surname capture via automatic speech recognition over the telephone has many commercial applications, including automated directory assistance and travel reservation services. This paper presents a usability evaluation of three different dialogue designs for automated surname capture, within the context of a flight reservation service. The three designs explored were: a Speak Only strategy, in which callers simply say the surname; a One Stage Speak and Spell strategy in which callers speak and spell the surname in a single utterance; and a Two Stage Speak and Spell strategy in which callers speak and spell the surname in two separate dialogue stages. The methodology employed in the research provides both quantitative user attitude data and performance results for each of the strategies, based on an empirical study with a cohort of 95 participants. The results show a clear distinction between strategies. User attitude towards the dialogues that involve both speaking and spelling the name is high. User attitude towards the Speak Only strategy is significantly less positive. Task completion rates are also significantly higher in the two strategies that involve spelling the name, at around 80% compared to just over 50% in the Speak Only strategy. The data underline the importance of user testing, demonstrating the value of the evaluation methodology used, and provide encouraging results for the strategies that involve both speaking and spelling the name. 2004 Elsevier B.V. All rights reserved.