Qualitative study of user annotations in satellite scheduling

Past research in scheduling has focused on algorithmic issues and has not addressed many important human-computer interaction issues. For tasks that require a higher level of abstraction and decision, annotation tools could provide an aid. This study investigated how people used annotations to solve problems presented on printed schedules. A user study involving 5 participants was conducted. Participants were presented with a pre-computed satellite schedule and given a practical problem to solve. Video observations, interview answers, and markings on the schedule and source documents provided data for analysis. Results show that while making trade-offs on different priorities, every participant used and benefited from the use of annotations. Participants did not always use specific annotations because of the connotations of the annotation appearance. The results suggest that support is needed for marking priority changes, deleted activities, interesting regions, and adding text on the schedule.