User Experience (UX) is a maturing research area pertaining to as well as extending beyond the traditional usability. Issues in the realm of usability may be amplified in UX because of its larger scope. Four key non-orthogonal issues are definition, modeling, method selection, and interplay between evaluation and development. Leveraging the legacy of a series of related research activities, this Special Issue (SI) aims to develop a deeper understanding of how evaluation feedback shapes software development, especially when experiential qualities such as fun, trust, esthetic values are concerned. Three articles addressing this specific topic from different perspectives and with different approaches are included in this SI.