This study compared the usability of 3 different metaphor-based versions of a speech
activated mobile city guide service. The effects of individual differences on attitude towards and performance with the mobile service were also explored. A Wizard of Oz methodology was used to provide the service functionality. All participants completed tasks with a standard control service, and then with one of the 3 metaphor-based services (shopping, office filing system, and transport system). Subjective and objective measures were recorded and analysed to compare services. The office filing system service was rated as being the most usable, and the transport system service least usable. Correlation data suggested that verbal ability and previous telephone experience may be important factors to consider when developing metaphor-based services.