Usability has become established as an important aspect of product design. This paper describes an investigation that was carried out to identify the importance of usability in product choice related to other product attributes. Interviews were initially carried out to identify possible attributes that contribute to product choice. Experiments were then undertaken using the methods of active information search, structured preference elicitation, ranking and interviews in order to find out what attributes were important to people when choosing an example product – mobile phones. It was found that usability is indeed important in product choice but perhaps not as much as users themselves believe. Other attributes that were found to be more important were features, aesthetics and cost. The process of product choice was found to be complex and it may be the case that people have come to expect usability in their products. Further research is needed to understand more fully the changing role of usability in product choice and to further improve the quality of the user–product relationship.

The Think Aloud Protocol (TAP) is a verbalisation technique widely employed in HCI user studies to give insight into user experience, yet little work has explored the impact that TAPs have on participants during user studies. This paper utilises a brain sensing technique, fNIRS, to observe the effect that TAPs have on participants. Functional Near-Infrared Spectroscopy (fNIRS) is a brain sensing technology that offers the potential to provide continuous, detailed insight into brain activity, enabling an objective view of cognitive processes during complex tasks. Participants were asked to perform a mathematical task under 4 conditions: nonsense verbalisations, passive concurrent think aloud protocol, invasive concurrent think aloud protocol, and a baseline of silence. Subjective ratings and performance measures were collected during the study. Our results provide a novel view into the effect that different forms of verbalisation have on workload during tasks. Further, the results provide a means for estimating the effect of spoken artefacts when measuring workload, which is another step towards our goal of proactively involving fNIRS analysis in ecologically valid user studies