Gary Marchionini

Exploratory search: from finding to understanding

Research tools critical for exploratory search success involve the creation of new interfaces that move the process beyond predictable fact retrieval.

Finding facts vs. browsing knowledge in hypertext systems

The authors discuss the role of information retrieval, interface design, and cognitive science in hypertext research. They present a user-centered framework for information-seeking that has been used in evaluating two hypertext systems. They apply the framework to key design issues related to information retrieval in hypertext systems.<<ETX>>

A self-organizing semantic map for information retrieval

Self-organizing Semantic Map for Information Retrieval Xia Lin Dagobert Soergel Gary Marchionini College of Library and Information Services University of Maryland College Park, A neural network’s unsupervised learning algorithm, Kohonen’s feature map, is applied to constructing a selforganizing semantic map for information retrieval. The semantic map visualizes semantic relationships between input documents, and has properties of economic representation of data with their interrelationships. The potentials of the semantic map include using the map as a retrieval interface for an online bibliographic system. A prototype system that demonstrates this potential is described.

Information-seeking strategies of novices using a full-text electronic encyclopedia

An exploratory study was conducted of elementary school children searching a full-text electronic encyclopedia on CD-ROM. Twenty-eight third and fourth graders and 24 sixth graders conducted two assigned searches, one open-ended, the other one closed, after two demonstration sessions. Keystrokes captured by the computer and observer notes were used to examine user information-seeking strategies from a mental model perspective. Older searchers were more successful in finding required information, and took less time than younger searchers. No differences in total number of moves were found. Analysis of search patterns showed that novices used a heuristic, highly interactive search strategy. Searchers used sentence and phrase queries, indicating unique mental models for this search system. Most searchers accepted system defaults and used the AND connective in formulating queries. Transition matrix analyses showed that younger searchers generally favored query refining moves and older searchers favored examining title and text moves. Suggestions for system designers were made and future research questions were identified.

The roles of digital libraries in teaching and learning

Libraries have long served crucial roles in learning. The first great library, in Alexandria 2,000 years ago, was really the first university. It consisted of a zoo and various cultural artifacts in addition to much of the ancient worlds written knowledge and attracted scholars from around the Mediterranean, who lived and worked in a scholarly community for years at a time. Today, the rhetoric associated with the National/Global Information Infrastructure (N/GII) always includes examples of how the vast quantities of information that global networks provide (i.e., digital libraries) will be used in educational settings [16].

Interfaces for End-User Information Seeking

Essential features of interfaces to support end-user information seeking are discussed and illustrated. Examples of interfaces to support the following basic information-seeking functions are presented: problem definition, source selection, problem articulation, examination of results, and information extraction. It is argued that present interfaces focus on problem articulation and examination of results functions, and research and development are needed to support the problem definition and information extraction functions. General recommendations for research on interfaces to support end-user information seeking include: attention to multimedia information sources, development of interfaces that integrate information-seeking functions, support for collaborative information seeking, use of multiple input/output devices in parallel, integration of advanced information retrieval techniques in systems for end users, and development of adaptable interfaces to meet individual difference and multicultural needs.

Previews and overviews in digital libraries: designing surrogates to support visual information seeking

To aid designers of digital library interfaces, we present a framework for the design of information representations in terms of previews and overviews. Previews and overviews are graphic or textual representations of information abstracted from primary information objects. Previews act as surrogates for one or a few objects and overviews represent collections of objects. A design framework is elaborated in terms of the following three dimensions: (1) what information objects are available to users, (2) how information objects are related and displayed, and (3) how users can manipulate information objects. When utilized properly, previews and overviews allow users to rapidly discriminate objects of interest from those not of interest, and to more fully understand the scope and nature of digital libraries. This article presents a definition of previews and overviews in context, provides design guidelines, and describes four example applications.

Key frame preview techniques for video browsing

Digitized video is an important format in digital libraries. Browsing video surrogates saves user time, storage capacity and avoids unnecessary downloading of large files. The study presented in this paper compared dynamic and static presentation techniques for key frames extracted from video documents. For this study key frames were automatically extracted and then a subset was manually selected to best represent the document. The three interface designs used were: 4 key frame static storyboard display, 12 key frame static storyboard display and 12 key frame dynamic slideshow display. The key frames in all displays were shown in temporal order. User performances on object, action identification, and gist comprehension and selection tasks were compared across treatments. Examination time and user satisfaction were also measured. Static storyboard displays proved to support object identification better, while other user performance measures showed no statistically significant differences. Using fewer key frames in static displays saved considerable amount of user time and screen real estate and user performance on gist comprehension and selection did not decrease when key frames were carefully selected to support queries. Implications for interface design and further research are discussed.

Evaluating hypermedia and learning: methods and results from the Perseus Project

The Perseus Project has developed a hypermedia corpus of materials related to the ancient Greek world. The materials include a variety of texts and images, and tools for using these materials and navigating the sytem. Results from a three-year evaluation of Perseus use in a variety of college settings are described. The evaluation assessed both this particular system and the application of the technological genre to information management and to learning. The evaluation used a variety of methods to address questions about learning and teaching with hypermedia and to guide the development of early versions of the system. Results illustrate that such environments offer potential for accelerating learning and for supporting new types of learning and teaching; that students and instructors must develop new strategies for learning and teaching with such technology; and that institutions must develop infrastructural support for such technology. The results also illustrate the importance of well-designed interfaces and different types of assignments on user performance.

The Open Video Digital Library

a variety of segmentation, indexing, and user interface techniques developed in the Almaden and Watson labs [Ponceleon et al., 1999], and the Digital Video Multimedia Group at Columbia, which has been engaged in several streams of work including efforts to automate video summaries [Chang et al., 1997]. The Multimedia Information Retrieval Group at Dublin City University has been developing the Fischlar Project, which provides broadcast video for the university community. This group has developed innovative user interfaces for Abstract