Abstract. There are a range of different usability evaluation methods: both analytical and empirical. The appropriate choice is not always clear, especially for new technologies. In-car navigation systems are an example of how multimodal technologies are increasingly becoming part of our everyday life. Their usability is important, as badly designed systems can induce errors resulting in situations where driving safety may be compromised. In this paper we use a study on the usability of a navigation device when the user is setting set up an itinerary to investigate the scope of different classes of approach. Four analytical and one empirical techniques were used to evaluate the usability of the device. We analyse the results produced by the two classes of approachanalytical versus empirical -and compare them in terms of their diversity and the insight they provide to the analyst in respect to the overall usability of the system and its potential improvement. Results suggest a link between genotypes and the analytical class of approach and phenotypes in the empirical class of approach. We also illustrate how the classes of approach complement each other, providing a greater insight into the usability of a system.