Designing a User-System Interface (USn is a complex task and has been approached in many ways. One approach has been to use USI design guidelines to help improve the quality and consistency of USIs. To use guidelines effectively, a general set of guidelines must be tailored to a specific application. One popular set of guidelines is the Smith and Mosier Guidelines for Designing User Interface Software (1986). This thesis investigated the effects of using a computer-based hypertext design aid (DRUID, Dynamic Rules for User Interface Design) for the selection of USI guidelines for both experienced and novice Guidelines users. Also, the relative usability of the software and hardcopy document was examined to improve the interface for the next iteration of DRUID. Both performance and variability in guideline selection strategies were studied within the context of the experimental tasks. Results indicate that subjects effectively used both the book and hypertext presentation media. However, subjects selected more relevant guidelines with the book. The media influenced the subjects' selection strategies, and the subjects read less when using DRUID. Subjectively, the software was preferred because it provided assistance in the selection process. The presentation of the guidelines could be improved for both media, and many of the factors which led subjects to select fewer relevant guidelines with DRUID could be overcome with improved USI design and implementation. Also, to overcome the limitations of presenting large texts on-line, "value added" features should be incorporated into on-line tools to help users better perform their tasks. / Master of Science