We investigated the role of domain structure, in designing for software usefulness and usability. We ran through the whole application development cycle, in miniature, from needs analysis through design, implementation, and evaluation, for planning needs of one NASA Mission Control group. Based on our needs analysis, we developed prototype software that matched domain structure better than did the legacy system. We compared our new prototype to the legacy application in a laboratory, high-fidelity analog of the natural planning work. We found large performance differences favoring the prototype, which better captured domain structure. Our research illustrates the importance of needs analysis (particularly Domain Structure Analysis), and the viability of the design process that we are exploring.

Knowledge workers making sense of a topic divide their time among activities including searching for information, reading, and taking notes. We have built a software system that supports and integrates these activities. To test its effectiveness, we conducted a study where subjects used it to perform medical question-answering tasks. Initial results indicate that subjects could use the system, but that the nature of this use depended on the subject's overall question-answering strategy. Two dominant strategies emerged that we call the Reader and Searcher strategies.