Exploring representation problems using hypertext

ABSTRACT

Hypertext is a technology well-suited to exploring different kinds of representational problems. It can be used first as an informal mechanism to describe the attributes of objects and to capture relationships between the objects. Then hypertext structures can be constrained into a more formal representation of a domain, model, or analytic technique. A range of strategies for using hypertext can be employed to describe a problem and converge on an appropriate representation; competing representations can be informally evaluated to compare their relative expressive power. This paper discusses several applications that have used NoteCards, a hypertext idea processing system, to tackle representation problems. Examples from each problem domain have been collected using the hypertext system as the initial acquisition vehicle. Subsequent analysis using hypertext structuring tools has revealed the semantics of each problem domain enabling the development of competing representations. Abstraction of the structure and form of these representations can be used to guide system extensions. These tailored extensions support the evaluation of a representation's relative merits; the representation that has been developed in response to a particular problem can be applied to analogous problems to determine the limits of its scope. The first application described in this paper models a type of policy decision-making process; the second looks at approaches to representing the logical structure of an argument; and the third suggests some methods for capturing the structure of a political organization as an alternative to a conventional database design. The applications are discussed in terms of the issues they raise and the trade-offs they involve, how hypertext-based tools have been used to exploit the representations, and the solutions and techniques that have been developed in the process of creating each representation.

REFERENCES

• Alli71: Allison, G., Essence of Decision: Explaining the Cuban Missile Crisis, Little, Brown and Company, Boston, Mass., 1971.
• Hala87: Frank G. Halasz , Thomas P. Moran , Randall H. Trigg, Notecards in a nutshell, Proceedings of the SIGCHI/GI conference on Human factors in computing systems and graphics interface, p.45-52, April 05-09, 1987, Toronto, Ontario, Canada
• Mars86: Marshall, C., "Representation of a rational actor model in NoteCards," Xerox Special Information Systems (internal report), Pasadena, California, July, 1986.
• Russ87: Ruaselt, D.M., Moran, T.P., and Jordan, D.S., "The Instructional Design Environment," to appear in Intelligent Tutoring Systems: Lessons Learned, J. Psotka, L.D. Massey, & S.A. Mutter (Eds), Lawrence Erlbaum Associates, Inc, Hillsdale, NJ, press.
• Toul58: Toulmin, S., The Uses of Argument, Cambridge University Press, Cambridge, 1958.
• Trig87: Trigg, R.H., Moran, T.P., and Halasz, F.G., "Adaptability and Tailorability in NoteCards" Proceedings of INTERACT-87, Stuttgart, West Germany, September, 1987.
• VanL85: VanLehn, K., "Theory reform caused by an argumentation tool," Xerox Palo Alto Research Center Technical Report, ISL-11, July, 1985.

INDEX TERMS

Primary Classification:
  H. Information Systems
  H.5 INFORMATION INTERFACES AND PRESENTATION (I.7)

Additional Classification:
  I. Computing Methodologies
  I.1 SYMBOLIC AND ALGEBRAIC MANIPULATION
      I.1.1 Expressions and Their Representation
          Subjects: Representations (general and polynomial)
  I.7 DOCUMENT AND TEXT PROCESSING
      I.7.2 Document Preparation
          Subjects: Hypertext/hypermedia

General Terms:
Design, Documentation, Languages, Management, Measurement, Performance, Theory