Measuring User Experience of Adaptive User Interfaces using EEG: A Replication Study

Background: Adaptive user interfaces have the advantage of being able to dynamically change their aspect and/or behaviour depending on the characteristics of the context of use, i.e. to improve user experience. User experience is an important quality factor that has been primarily evaluated with classical measures (e.g. effectiveness, efficiency, satisfaction), but to a lesser extent with physiological measures, such as emotion recognition, skin response, or brain activity. Aim: In a previous exploratory experiment involving users with different profiles and a wide range of ages, we analysed user experience in terms of cognitive load, engagement, attraction and memorisation when employing twenty graphical adaptive menus through the use of an Electroencephalogram (EEG) device. The results indicated that there were statistically significant differences for these four variables. However, we considered that it was necessary to confirm or reject these findings using a more homogeneous group of users. Method: We conducted an operational internal replication study with 40 participants. We also investigated the potential correlation between EEG signals and the participants' user experience ratings, such as their preferences. Results: The results of this experiment confirm that there are statistically significant differences between the EEG variables when the participants interact with the different adaptive menus. Moreover, there is a high correlation among the participants' user experience ratings and the EEG signals, and a trend regarding performance has emerged from our analysis. Conclusions: These findings suggest that EEG signals could be used to evaluate user experience. With regard to the menus studied, our results suggest that graphical menus with different structures and font types produce more differences in users' brain responses, while menus which use colours produce more similarities in users' brain responses. Several insights with which to improve users' experience of graphical adaptive menus are outlined.