ACM Computing Surveys
31(4), December 1999,
http://www.acm.org/surveys/Formatting.html. Copyright ©
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Hypermedia: A Design Philosophy
Hypermedia Research Laboratory
Computer and Information Science Department
University Heights, Newark, New Jersey 07102 U.S.A.
Web: http://www-ec.njit.edu/~bieber Rutgers University
Graduate School of Management
University Heights, Newark, New Jersey 07102 U.S.A.
Hypermedia: A Design Philosophy
How often do you want to point to an object on the computer screen and say "This looks interesting. Tell me more about it. What is it? How can I use it? What do I need to know to use it? Can I modify it? What can I do once I have deployed it? How does it differ from other similar objects?" These are all relationships, and we should be able to access them.
Yet, few designers explicitly think about their applications' interrelationships and whether users should access and navigate them directly. Why not? In part, it has not occurred to many designers and developers to incorporate hypermedia functionality [Bieber 2000b] . (Hypermedia can be viewed as the science of relationship management [Isakowitz 1995] - structuring and navigating information through relationships, i.e., links.) Most designers and developers do not have a hypermedia mindset; they and their users have seen few examples and do not demand this functionality yet. In part, people do not have the time to reengineer existing applications, especially when migrating them to the World Wide Web with other projects waiting in the wings. Developers also have few tools and techniques for designing and incorporating hypermedia functionality easily. Developers will not do this until it is natural to conceive and easy to implement [Bieber 1997].
Science fiction writers fantasize about people who vividly can see the relationships among people and objects. Designers should do this naturally for their information domains. But they rarely do. When the first author did a relationship analysis on an application he had used extensively for several years, in a period of two hours he discovered over twenty useful types of information, which clearly should have been directly accessible within the system [Bieber 2000]. As further anecdotal evidence, this happened again when in the space of a few hours, an expert in decision analysis greatly expanded his prototype's design with several extremely intuitive relationships, which he had failed to see in years of previous work.
Designers appear not have a deep enough conceptualization of their domains to identify intuitive relationships. It seems they need help in realizing the full scope and interconnections within their domains [Anderson 2000]. Yet, no approaches exist for determining the relationships within an information domain or system. Such an analysis should precede the design phase, which many of the hypermedia design methodologies address [Balasubramanian 2000], [Christodoulou 1998], [Garzotto 1993], [Isakowitz 1995], [Lange 1996], [Schwabe 1996].
The goal of our research is to help designers and developers develop a hypermedia mindset by giving them an analysis tool, RNA (Relationship-Navigation Analysis), to think about an information domain in terms of its interrelationships [Yoo 2000]. Hypermedia links represent relationships in applications. Once identified, our DHymE hypermedia engine can generate links for many of these relationships automatically [Bieber 2000]. Over time, we aim to establish new standards for the application development process and for users' interaction with applications. Designers should conduct a relationship analysis in order to more deeply understand the relationship structure of their applications and generate a full range of links to implement. Users should be able to point to any object of interest and find out whatever they want about it through these links.
A hypermedia mindset promotes both a design philosophy and a philosophy of maximum access based on relationships. Granting users full freedom to access and explore at will helps them better understand a domain as a whole and build confidence in application results. Under this philosophy, any element of interest to a user should be a candidate for linking. RNA supports a hypermedia philosophy of design, which embodies a systematic approach to realizing a philosophy of maximum access within computer applications [Yoo 2000].
The RNA approach has five steps: stakeholder analysis, element of
interest analysis, relationship analysis, navigation analysis and
feasibility analysis. Designers employ RNA as a knowledge elicitation
or brainstorming tool, using it as a framework or set of categories
with which to examine their application and its information
environment. During stakeholder analysis, designers determine everyone
who will use some aspect of the application. This can produce
surprising revelations. For example, when designing a university
class web site, we realized that stakeholders included the department
chair at evaluation time, high school students considering our
university and colleagues at other universities interested in what we
are doing. During element of interest analysis we determine what each
stakeholder might want to find out more about. Table
1 shows RNA's general relationship taxonomy. During the
relationship analysis stage, each generic relationship provides a
series of questions which designers can ask themselves about each
element of interest for a given stakeholder. During navigation
analysis, designers then think of each element of interest in terms
of how the stakeholder might usefully access it, e.g., as part of an
index, guided tour or customized trail. During feasibility analysis,
designers do an informal cost/benefit analysis to decide which
relationships would be useful and feasible enough to actually include
in the application design. For some the information a relationship
may point to might be impractical to implement. Designers should feel
cognitively unbounded during the first four stages of the analysis,
putting off practical constraints to the last stage.
Table 1: RNA's General Relationship Taxonomy
Space constraints prohibit a full discussion of RNA here, so we illustrate with just a few example questions using the RNA relationship taxonomy during the relationship analysis stage. Suppose we are building a repository of multimedia components for on-line courses. The taxonomy's descriptive relationship might prompt us to ask whether course components have a description, definition, explanation, set of instructions, documentation or illustrations available, within or external to the system. Any or all could be implemented later as links. The taxonomy's occurrence relationship would prompt us to ask "What are all the course topics that would use this component. Show me all courses that currently use it." The attribute/parametric relationship prompts questions such as "What are the component's inputs and outputs? Which media types does it use? What software do I need to execute it? What operating system does it require? How much space and memory does it need? How long does it take to use? How do I implement it? What assumptions underlie it?" The ordering relationship would prompt us to ask "what prerequisites exist for this component? What logically follows it for a given user's (student, teacher, courseware developer) purpose?" The similar/dissimilar relationship prompts the questions "Which other components are similar to this one, and in which ways?" The developer could decide to implement any or all of these later as links, but even if, they would gain a deeper understanding of how components fit in that domain.
Our goal is to ascertain a complete taxonomy of generic relationship types that would apply to any application domain. Part of proving this will be to show that any other link or relationship taxonomy--domain independent or domain specific--would map clearly to ours. Then we need to conduct experiments and field studies to show that RNA indeed produces richer analyses, than if designers did no relationship analysis. Kopak [Kopak 2000] also is developing a link taxonomy, and we look forward to comparing it, once complete, to ours.
But we wonder if RNA has a deeper role, serving perhaps as a generic ontology of relationships in any complex system--computerized or otherwise. How often do you hear a remark, see cursory mention of something in a magazine article, spot something interesting in a catalog, see a component in a diagram or blueprint, stumble across an item in a supermarket, and want to say "Tell me more about this!"? The longer we work on RNA, the more we find ourselves questioning the relationships of the objects and systems surrounding us in the everyday world. This hypermedia vantage point makes the world a richer place for us. Would that all our computer applications were this rich.
We gratefully acknowledge funding for this line of research by the NASA JOVE faculty fellowship program, by the New Jersey Center for Multimedia Research, by the National Center for Transportation and Industrial Productivity at the New Jersey Institute of Technology (NJIT), by the New Jersey Department of Transportation, and by the New Jersey Commission of Science and Technology, and by Rutgers University.
References[Anderson 2000] Kenneth A. Anderson. "Supporting Software Engineering with Open Hypermedia Systems" in ACM Computing Surveys Symposium on Hypertext and Hypermedia, 2000.
[Balasubramanian 2000] V. Balasubramanian, Michael Bieber, and TomĚs Isakowitz. "Systematic Hypermedia Design" in Information Systems Journal [Online: http://www.cis.njit.edu/~bieber/pub/ISJ98/isj98.pdf], 1998.
[Bieber 1997] Michael Bieber and Fabio Vitali. "Toward Support for Hypermedia on the World Wide Web" in IEEE Computer, 30(1), 62-70, [Online: http://www.cs.unibo.it/~fabio/bio/papers/1997/IEEEC97/January/IEEEC0197.html ], 1997.
[Bieber 2000] Michael Bieber. "Supplementing Applications with Hypermedia" in submission. [Online: http://www.cis.njit.edu/~bieber/pub/supp/supp.html], 2000.
[Bieber 2000b] Michael Bieber, Harri Oinas-Kukkonen, and V. Balasubramanian. "Hypertext Functionality" in ACM Computing Surveys Symposium on Hypertext and Hypermedia, 2000.
[Christodoulou 1998] Sotiris P. Christodoulou, George D. Styliaras, and Theodoro S. Papatheodorou. "Evaluation of Hypermedia Application Development and Management Systems" in Proceedings of ACM Hypertext '98, Pittsburgh, PA, 1-10, June 1998.
[Garzotto 1993] Franco Garzotto, Paulo Paolini, and Daniel Schwabe. "HDM - A Model-Based Approach to Hypertext Application Design" in ACM Transactions on Information Systems (TOIS) 11(1), 1-26, 1993.
[Isakowitz 1995] TomĚs Isakowitz, Edward Stohr, and P. Balasubramanian. "RMM: A Methodology for Structuring Hypermedia Design" in Communications of the ACM (CACM), 38(8), 34-44, August 1995.
[Kopak 2000] Richard Kopak. "A Proposal for a Taxonomy of Link Types" in ACM Computing Surveys Symposium on Hypertext and Hypermedia, 2000.
[Lange 1996] Danny Lange. "Object-Oriented Hypermodeling of Hypertext Supported Information Systems" in Journal of Organizational Computing and Electronic Commerce 6(3), 269-293, 1996.
[Schwabe 1996] Daniel Schwabe, Gustavo Rossi, and Simone D. J. Barbosa. "Systematic Hypermedia Application Design with OOHDM" in Proceedings of ACM Hypertext'96, Washington, DC, 116-128, March 1996.
[Yoo 2000] Joonhee Yoo and Michael Bieber. "Towards a Relationship Navigation Analysis" in Hawaii International Conference on Systems Sciences, [Online: http://www.cis.njit.edu/~bieber/pub/hicss00/hicss00.html], January 2000.
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