Identifying regularities in users' conceptions of information spaces: Designing for structural genre conventions and mental representations of structure for Web-based newspapers

Despite gains in our understanding of users' problems with digital documents, users are still faced with disorientation and demanding navigation in complex information spaces. This dissertation seeks to address these problems by posing the following research question: What genre conventions facilitate the development of mental representations of structure for information spaces? The research question is further refined by proposing to study one kind of information space, web-based newspapers.; A two phase study was conducted, where phase one was a focus group and expert review. The focus group was conducted with expert readers of web-based news who were also producers of web pages. From this focus group, two web site designs were derived: one 'ideal' example of a web based newspaper, and one 'non-ideal' example of a web-based newspaper. These two designs were reviewed by an expert panel of human-computer interaction, cognitive science, and computer science researchers. Based on this review, additional modifications to the non-ideal design were suggested to enhance the difference between the two designs.; Phase two was a longitudinal experiment with a group of 25 novice web news readers who were exposed to one of the two designs over 5 sessions. During these sessions a variety of user data were captured, including: comprehension, usability, navigation, and visual depictions of the web site.; The between-group difference of web site design was significant for comprehension, usability, and navigation with the users of the ideal design demonstrating better performance. The within-group difference of time was significant across these three measures as well, with performance improving over time. No interaction effect was found between web site design and time on comprehension or usability. However, a surprising interaction effect was found on navigation. By examining the changes in these data over time and between the two designs, evidence for the development of users' mental representations of structure was captured.