Sherry Koshman

Much research has been devoted to collaborative tools for writing, group communication, reviewing, managing projects, and developing network infrastructures to support sharing activities. However the creation and display of foundational collaborative concepts that manage group work has not been paid significant attention. Information visualization potentially addresses the progression of distributed concept building and presentation by visually representing groupgenerated concepts. This paper analyzes current visualizationbased techniques including tag clouds, node-link diagrams, and mapping structures in a web-based environment. The analysis contributes to exploring the use of visualization tools for creating group concept structures that organize ideas for documents, projects, or specifications in academia and industry. A comparative features table is built and used as a basis for presenting an initial interface design to develop a collaborative visualization tool for concept management. Implications for future work include visualization system interface design, user evaluation, and adaptation to mobile collaborative visualization environments.

Detecting query reformulations within a session by a Web searcher is an important area of research for designing more helpful searching systems and targeting content to particular users. Methods explored by other researchers include both qualitative (i.e., the use of human judges to manually analyze query patterns on usually small samples) and nondeterministic algorithms, typically using large amounts of training data to predict query modification during sessions. In this article, we explore three alternative methods for detection of session boundaries. All three methods are computationally straightforward and therefore easily implemented for detection of session changes. We examine 2,465,145 interactions from 534,507 users of Dogpile.com on May 6, 2005. We compare session analysis using (a) Internet Protocol address and cookie; (b) Internet Protocol address, cookie, and a temporal limit on intrasession interactions; and (c) Internet Protocol address, cookie, and query reformulation patterns. Overall, our analysis shows that defining sessions by query reformulation along with Internet Protocol address and cookie provides the best measure, resulting in an 82% increase in the count of sessions. Regardless of the method used, the mean session length was fewer than three queries, and the mean session duration was less than 30 min. Searchers most often modified their query by changing query terms (nearly 23% of all query modifications) rather than adding or deleting terms. Implications are that for measuring searching traffic, unique sessions may be a better indicator than the common metric of unique visitors. This research also sheds light on the more complex aspects of Web searching involving query modifications and may lead to advances in searching tools.

The application of clustering to Web search engine technology is a novel approach that offers structure to the information deluge often faced by Web searchers. Clustering methods have been well studied in research labs; however, real user searching with clustering systems in operational Web environments is not well understood. This article reports on results from a transaction log analysis of Vivisimo.com, which is a Web meta‐search engine that dynamically clusters users' search results. A transaction log analysis was conducted on 2‐week's worth of data collected from March 28 to April 4 and April 25 to May 2, 2004, representing 100% of site traffic during these periods and 2,029,734 queries overall. The results show that the highest percentage of queries contained two terms. The highest percentage of search sessions contained one query and was less than 1 minute in duration. Almost half of user interactions with clusters consisted of displaying a cluster's result set, and a small percentage of interactions showed cluster tree expansion. Findings show that 11.1% of search sessions were multitasking searches, and there are a broad variety of search topics in multitasking search sessions. Other searching interactions and statistics on repeat users of the search engine are reported. These results provide insights into search characteristics with a cluster‐based Web search engine and extend research into Web searching trends.

We investigate the occurrence of Web searchers returning the same information course, in this case the Vivisimo Web search engine. We analyze data from a transaction log spanning a roughly 8‐day period with approximately 1,200,000 records. During this time 40,227 users made repeated daily visits to the search engine, submitting 648,897 queries. Our findings show that repeat users make up about 21% of the user base. These repeat users account for over 45% of all sessions and nearly 60% of all queries submitted. Most repeat users (46%) visited the search engine on two days during the data collection period, but a sizeable percentage (17%) made 5 or more daily visits to Vivisimo. We discuss the implications for successive searching and future research.