Steven J. Shute

Knowledge-based search tactics

Abstract As part of the knowledge engineering activities for building a computerized intermediary search system, an empirical study was conducted to gain insights into the performance of an expert human intermediary. Based on her interactions with 17 information seekers, a model was developed that describes certain ways in which she used subject-specific knowledge to help them refine their topics. In this model, suggestions for topic refinement are generated by applying certain knowledge-based search tactics to a specific type of knowledge-structure (frames). The intermediarys performance during the 17 search sessions can be described as including 328 applications of such tactics. The insights gained from these results have potentially important implications for the design of computerized intermediary systems, as well as for the training of human intermediaries.

Knowledge-based search tactics for an intelligent intermediary system

Research on the nature of knowledge-based systems for bibliographic information retrieval is summarized. Knowledge-based search tactics are then considered in terms of their role in the functioning of a semantically based search system for bibliographic information retrieval, EP-X. This system uses such tactics to actively assist users in defining or refining their topics of interest. It does so by applying these tactics to a knowledge base describing topics in a particular domain and to a database describing the contents of individual documents in terms of these topics. This paper, then, focuses on the two central concepts behind EP-X: semantically based search and knowledge-based search tactics.

Effects of Video Display Terminals on Telephone Operators

A self-administered questionnaire was completed by 145 Directory Assistance operators who used video display terminals (VDTs) to retrieve listings and by 105 control subjects who performed identical work except that they retrieved listings from printed paper records. The two groups exhibited few differences in their experience of work-related physical discomfort, in job satisfaction, or in their concerns about job security. Both groups were found to use eyeglasses and contact lenses to the same extent. VDT operators generally did not obtain special corrective lenses for work. The results show that replacing paper documents with VDTs need not adversely affect the comfort and morale of office workers.

Effects of adjustable furniture on VDT users.

Telephone operators served as their own controls in two field studies of advanced furniture designed for video display terminal (VDT) workstations. The advanced furniture was characterized by dimensions that were easily adjusted by users, in contrast with conventional furniture that provided either no adjustments or inconvenient adjustments that could only be made with difficulty. An eight-week study focused on advanced VDT tables, and a fiveweek study focused on advanced chairs. Four combinations of advanced and conventional workstation components were compared. Although on-the-job discomfort was reduced when either conventional component was replaced with an advanced component, the effect was far greater when the advanced table and the advanced chair were used together. The adjustments of the advanced furniture were reported to be easy to use, and the advanced furniture was rated more highly than the conventional furniture.

EP-X: a demonstration of semantically based search of bibliographic databases

EP-X (Environmental Pollution eXpert) is a prototype knowledge-based system that assists users in conducting bibliographic searches of the environmental pollution literature. This system combines artificial intelligence and human factors engineering techniques, allowing us to redesign traditional bibliographic information retrieval interfaces. The result supports semantically-based search as opposed to the typical character-string matching approach. This paper discussesa sample interaction with EP-X, the knowledge representations necessary to support this semantically-based interaction, preliminary results of empirical studies to evaluate the interface, and recommendations for future directions

In search of knowledge-based search tactics

Knowledge-based search tactics are discussed in terms of their role in the functioning of a semantically-based search system for bibliographic information retrieval. This prototype system, EP-X, actively assists users in defining or refining their topics of interest. It does so by applying search tactics to a knowledge-base describing topics in a particular domain and a database describing the contents of individual documents. This paper reviews the empirical studies that lead to the two central concepts implemented in EP-X:Semantically-based search;Knowledge-based search tactics.

Cognitive Engineering Issues in the Design of a Knowledge-Based Information Retrieval System

EP-X (Environmental Pollution expert) is a prototype expert system that acts as an expert search intermediary for a bibliographic information retrieval system. It searches for documents in the Chemical Abstracts database in the domain of environmental pollution, providing an intelligent human-computer interface that accommodates a wide variety of user backgrounds and interests. This paper discusses 1) the general problem of bibliographic information retrival, 2) the value of combining Artificial Intelligence (AI) and Human Factors Engineering (HFE) techniques in the design of an intelligent human-computer interface. 3) the general architecture and functioning of EP-X, and 4) examples of specific issues that arise when attempting to apply both AI and HFE techniques to the design of an interactive computer system.

Knowledge Acquisition Techniques: A Case Study in the Development of a Knowledge-Based System for Document Retrieval

A case study is presented describing and illustrating the use of a number of knowledge acquisition techniques for the development of a knowledge-based system. The system developed is a computerized intermediary to assist in searches of bibliographic databases. Particular emphasis is placed on a discussion of the use a conceptual model to guide in the design and analysis of an empirical study of the expertise used by human search intermediaries. The framework provided by this model made it possible to conduct a rigorous analysis of discourses that were recorded as human intermediaries assisted information seekers.