Spoken help for a car stereo: an exploratory study

This paper reports an investigation of the use of spoken (audible) help in an attempt to increase the usability and learnability of a high-end car stereo. To investigate the usefulness of audible spoken help for a car stereo, a simulation was constructed within which experimental help systems were incorporated. To validate the simulation, the 'real' car stereo (an existing consumer product, acting as the control condition) was compared empirically with its simulation. An experiment, using the four conditions of actual product, simulation of actual product, and two simulations employing different spoken help functions was undertaken. Forty participants in a between subjects design, carried out specified tasks with the car stereo version according to experimental condition. User performance, specifically task completion and number of button presses, and subjective reactions were measured. The simulated spoken help versions clearly assisted users with their tasks, and, in general, were responded to favourably when compared to performance with the control simulation and its product equivalent. This exploratory study provided further insight into users' concerns about car stereo usability and the overall results revealed the potential of spoken help facilities for novice users. We can conclude that the use of audible, spoken help, whether as a global option or as a specific 'button help', enhances the performance of, and is acceptable to, novice users of this consumer product type. Finally, this investigation also demonstrated that the use of a (Hypercard) simulation versus the 'real' counterpart (the simulated car stereo) to be generally valid and appropriate for this type of evaluation. In order to progress this direction, examination of the design of spoken help dialogues, user control of these, and issues concerning 'longitudinal' use of the product type are recommended.