While human-computer interaction design patterns are created to support the design of user interfaces, there is lack of substantial evidence to support these promises. This thesis reports two exploratory observational studies, conducted to understand how patterns are used and whether they are of any benefit. Professional designers were encouraged to take advantage of a collection of user experience (UX) patterns while designing a social media application. Data on pattern reading were collected with eye-tracking. In Study 1, it was found that pattern use varied considerably amongst individual designers. All subjects found the patterns inefficiently presented, but designers who read them while designing saw them as helpful for getting inspiration. It was noted that varied use of patterns is a potential explanation to the minor effects of patterns in previous research. The procedure was repeated in Study 2, which gave similar results. Furthermore, it was shown that the extent to which patterns were read strongly correlated with design quality in a small sample of five expert designers. Causality was explained. No trend was identified among four novice designers. In Study 2 it was concluded that UX patterns can improve design quality with respect to UX when used for generation of ideas.