Trade-off between context and objectivity in an analytic approach to the evaluation of in-vehicle interfaces

This study presents a case study to explore an analytic approach to the evaluation of in-vehicle information system (IVIS) usability, aimed at an early stage in product development with low demand on resources. Five methods were selected: hierarchical task analysis (HTA), multimodal critical path analysis (CPA), systematic human error reduction and prediction approach (SHERPA), heuristic analysis and layout analysis. The methods were applied in an evaluation of two IVIS interfaces: a touch screen and a remote controller. The findings showed that there was a trade-off between the objectivity of a method and consideration of the context of use: this has implications for the usefulness of analytic evaluation. An extension to the CPA method is proposed as a solution to enable more objective comparisons of IVIS, whilst accounting for context in terms of the dual-task driving environment.