This document discusses evaluating user experience (UX). It provides an overview of UX research approaches including those that view UX as fundamental cognitive constructs and those that see it as unique to individual contexts. The document also presents a framework for attractiveness in UX and describes experiments examining how aesthetics, customization and virtual characters influence engagement. It concludes that UX is multifaceted and can be systematically evaluated through observation, questionnaires and physiological measures over time.