UX_Mate: From Facial Expressions to UX Evaluation

In this paper we propose and evaluate UX_Mate, a non-invasive system for the automatic assessment of User eXperience (UX). In addition, we contribute a novel database of annotated and synchronized videos of interactive behavior and facial expressions. UX_Mate is a modular system which tracks facial expressions of users, interprets them based on pre-set rules, and generates predictions about the occurrence of a target emotional state, which can be linked to interaction events. The system simplifies UX evaluation providing an indication of event occurrence. UX_Mate has several advantages compared to other state of the art systems: easy deployment in the user's natural environment, avoidance of invasive devices, and extreme cost reduction. The paper reports a pilot and a validation study on a total of 46 users, where UX_Mate was used for identifying interaction difficulties. The studies show encouraging results that open possibilities for automatic real-time UX evaluation in ecological environments.