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Hypermedia Research Laboratory
Computer and Information Science Department
University Heights, Newark, New Jersey 07102 U.S.A.
Web: http://www-ec.njit.edu/~bieber University of Oulu
Department of Information Processing Science
FIN-90570 Oulu, Finland
Email: Harri.Oinas-Kukkonen@oulu.fi, Contexture, Inc.
The Hypertext Functionality field [HTF 1999] studies techniques for and the impact of supplementing everyday computer applications with hypertext functionality (HTF). We view hypertext as value-added support functionality [Oinas-Kukkonen 1995]. Hypertext structuring, annotation and navigational functionality can enrich business, scientific, engineering and personal applications, thereby making them more effective. People use these applications primarily for their underlying analytical functionality, i.e., not for their ability to produce hypertext documents or displays. People will not abandon the applications they use everyday in favor of those that offer hypertext. Developers therefore must find it relatively easy to retrofit HTF to existing applications, as well as incorporate HTF into new ones. HTF should be integrated and deployed so seamlessly that users do not find its presence at all out-of-place. Augmenting applications with direct access and hypertext structuring, annotation and navigation functionality [Bieber 1997] should result in new ways to: view an application's knowledge and processes conceptually; navigate among items of interest and task stages; enhance an application's knowledge with comments and relationships; and target information displays to individual users and their tasks.
Hypertext structuring functionality includes local and global
information overviews; alternate views and contexts; transclusions
that preserve context by "including" the original content at all
places that use it and maintaining links between all these uses; link
propagation; node, link and anchor typing; as well as keywords and
other attributes on all of these. Navigation encompasses access
ranging from information retrieval to browsing. This includes
content- and structure-based query; history-based navigation and
sophisticated backtracking; bi-directional linking; dynamic and
computed linking; and process enactment or execution through link
traversal. Annotation includes bookmarks, landmarks, manual linking
and commenting. Note that many of these features can be shared in
collaborative environments. Many also can be personalized for
different users and tasks. We consider the terms hypertext and
hypermedia synonymous. Nominally hypertext refers to relating textual
elements, while hypermedia encompasses relationships among elements
of any media type. The concepts are identical, though hypertext is
more difficult to implement in non-textual media.
Figure 1: An Information System (after [Alter 1996] )
The HTF field can be viewed as a subfield of information systems, which studies most aspects of applying information technology (IT) effectively. Alter [Alter 1996] defines an information system as a collaboration among IT, data and human participants that supports or implements various tasks or "work processes" in order to produce services or products that benefit a customer or client. See Figure1. (Computer applications comprise the computerized portion of the information system and can encompass computerized products and services.) During the design stage, hypertext design techniques can help participants plan more effective application design. For implementation, hypertext constructs and functionality can provide value-added features to the application, including enacting its work processes [Noll 1996], [Noll 1999]. When clients interact directly with the information system, HTF can enhance their access to the application's data, meta-information and processes.
HTF builds upon general hypertext research. Whereas most hypertext research concentrates on building hypertext-specific applications, the HTF approach supplements the design, implementation and services of other, everyday applications.
The HTF approach fosters three major areas of research:
1. using HTF to improve personal and organizational effectiveness
2. HTF and application design
3. integrating HTF into applications
Using HTF to Improve Personal and Organizational Effectiveness
HTF, when well designed, can improve users' comprehension [Thüring 1995]. Presenting information as a web of interrelated items enables readers to access information in the order most appropriate to their purposes. Hypertext links and structural features provide a rich context of related information and meta-information around information elements. Freedom of access within a web enhanced with contextual information provides a richer environment for understanding the information people find. Some applications can generate links and meta-information automatically; in others, authors and developers can add these manually. Following hypertext links can help users build a more complete mental model of a domain, thereby reducing ambiguity [Daft 1986], [Isakowitz 1993].
Hypertext also can improve individual and organizational memory [Kuutti 1998]. Annotation functionality allows any user to add comments and additional links within applications, which can be private or shared among a work group. Hypertext structuring can help organize discussions around any element of interest (e.g., using argumentation tools [Conklin 1989], [Selvin 1999]).
Comprehension and memory enhancement are relatively intangible benefits. HTF's impact, therefore, on individuals and especially on organizations is difficult to measure. Even though some evaluations of HTF exist, for example 24, it remains an important and under-researched topic.
HTF and Application Design
This encompasses two separate topics. HTF can improve the design process, and designers can incorporate HTF into their application designs. For example, [Balasubramanian 1998b] models the early, creative idea generation phase of the user interface design process as a hypertext network of design tasks linked to each other in a specific manner. Traversing this network enables the designer to complete these design tasks in any order, generating a set of intermediate design outputs, which together form the user interface design document. This document can later be used for prototyping. Similarly, [Noll 1996] describes how software processes can be represented as hypertext graphs that can be enacted to produce software artifacts. [Bieber 2000a] provides a relationship-based analysis technique for determining the relationship structure of any information domain. This analysis, in turn, helps designers understand their domain more deeply, and produce richer designs. Many hypertext design methodologies help the designer determine and specify an application's content and navigational structure [Garzotto 1993], [Isakowitz 1995], [Lange 1996], [Schwabe 1996]. Using them produces links and navigational features within the design. The hypertext design methodologies produce new hypertext applications. Little research addresses retrofitting existing applications with HTF [Oinas-Kukkonen 2000]. Another important aspect of design is evaluating the resulting application. Some techniques exist for evaluating hypertext links and applications. No techniques exist yet for evaluating hypertext support of non-hypertext systems.
Integrating HTF into Applications
Several techniques exist for providing information systems with hypertext support [Oinas-Kukkonen 1995]. With HTF, the emphasis is on providing hypertext support for non-hypertext systems. The HTF approach especially serves analytical or "computational" applications, which dynamically generate their content as a result of user interaction (e.g., a database management system) [Bieber 1995], [Schnase 1989]. Links and other HTF must be mapped to documents and views being generated dynamically in real time, as opposed to being added manually. Often links cannot simply be mapped based on a keyword, rather they must be associated with an underlying object with no fixed display text (such as the current price of a particular stock.) Here hypertext links and other HTF must be coordinated in real time as applications are generating documents and views for display. This raises interesting issues regarding when links and other hypertext features can be pre-computed and when they must be generated as they are about to be displayed [Ashman 1997]. Of course, users still should be able to augment these computational applications with hand-crafted links as well as annotation and structural HTF.
We distinguish between intra-application HTF and inter-application HTF. While this emphasis is a design issue regarding the intended scope of relationship management and other HTF support for an application, it also impacts the implementation approach. With intra-application HTF support, developers implement all HTF in the application itself or in a proprietary way that serves a suite of associated applications (say, if Microsoft were to provide full HTF support for its MS Office suite). Developers could use toolkit approaches to implement intra-application HTF [Anderson 1996], [Puttress 1990], [Sherman 1990].
Inter-application HTF support requires an external engine [Bieber 1998b], [Garrido 1996] or Open Hypertext Systems-style link services or hyperbases [Davis 1994], [Whitehead 1997]. These execute independently of the application, which must communicate with them in some way to gain HTF. Developers also can construct intra-application HTF with these tools. Research in the area of Open Hypermedia Systems [Nürnberg 1998], 25 primarily focuses on building middleware components or engines, which provide hypermedia functionality to tools orthogonal to their storage and display functionality [Wiil 1999]. Using the services of an OHS, existing tools in the computing environment can be "hypermedia-enabled", without altering the information itself.
HTF: The Promise
Why is HTF not more prevalent [Bieber 1997a] ? In part, it has not occurred to many designers and developers to incorporate HTF. Most of them do not have a hypertext mindset; they and their users have seen few examples and do not demand this functionality yet. In part, people rarely have the time to reengineer applications beyond their current capabilities. And, in part developers have few tools and techniques to incorporate HTF easily. Few system developers actively think about an application's interrelationships, and whether users should access and navigate along these relationships directly. HTF research seeks to remedy all these problems. When well implemented, HTF support should make the applications that people use every day richer and more effective. This is the promise of the HTF approach, and we expect, the future of application development.
Dr. Bieber gratefully acknowledges funding for his HTF work 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.
References[Alter 1996]< Steven Alter. "Basic Ideas for Understanding Information Systems" in Information Systems: A Management Perspective, 2nd Edition, Benjamin Cummings, 1-9, 1996.
[Anderson 1996]< Kenneth M. Anderson. "Providing Automatic Support for Extra-Application Functionality" in Proceedings of the Second International Workshop on Incorporating Hypertext Functionality Into Software Systems (HTF II), ACM Hypertext '96 Washington DC, March 1996.
[Ashman 1997]< Helen Ashman, Alejandra Garrido, and Harri Oinas-Kukkonen. "Hand-made and Computed Links, Precomputed and Dynamic Links" in Proceedings of Multimedia '97 (HIM '97), Germany, 191-208, 1997.
[Balasubramanian 1998b]< V. Balasubramanian, Murray Turoff, and David Ullman. "A Systematic Approach to Support the Idea Generation Phase of the User Interface Design Process," Proceedings of the Thirty-First Hawaii International Conference on System Sciences, January 1998, Maui, Hawaii, Volume VI.
[Bieber 1995]< Michael Bieber and Charles J. Kacmar, "Designing Hypertext Support for Computational Applications," Communications of the ACM (CACM), 38(8), 99-107, August 1995.
[Bieber 1997]< Michael Bieber and Fabio Vitali. "Toward Support for Hypermedia on the World Wide Web" in IEEE Computer, 30(1), 62-70, 1997.
[Bieber 1997a]< Michael Bieber, Fabio Vitali, Helen Ashman, V. Balasubramanian and Harri Oinas-Kukkonen. "Fourth Generation Hypermedia: Some Missing Links for the World Wide Web" in International Journal of Human Computer Studies, 47 (1), 31-65 [Online: http://www.hbuk.co.uk/ap/ijhcs/webusability/], July 1997.
[Bieber 1998b]< Michael Bieber. "Hypertext and Web Engineering" in Proceedings of ACM Hypertext '98, Pittsburgh PA, 277-278, June 1998.
[Bieber 2000a]< Michael Bieber and Joonhee Yoo. "Hypermedia: A Design Philosophy" in ACM Computing Surveys, Symposium on Hypertext and Hypermedia, 2000.
[Conklin 1989]< Jeff Conklin and Michael L. Begeman. "gIBIS: A Tool for All Reasons" in Journal of the American Society for Information Science, 40(3), 200-213, 1989.
[Daft 1986]< Richard L. Daft and Robert H. Lengel. "Organizational Information Requirements, Media Richness and Structural Design" in Management Science, 32(5), 554-571, 1986.
[Davis 1994]< Hugh C. Davis, Simon Knight, and Wendy Hall. "Light Hypermedia Link Services: A Study of Third-Party Application Integration" in Proceedings of ACM European Conference on Hypermedia Technologies (ECHT)'94, Edinburgh, Scotland, 41-50, September 1994.
[Garrido 1996]< Alejandra Garrido and Gustavo Rossi, A framework for extending object-oriented applications with hypermedia functionality. The New Review of Hypermedia and Multimedia 2, 1996, 25-41.
[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.
[HTF 1999]< Hypertext Functionality Homepage [on-line: http://www.ep.cs.nott.ac.uk/~hla/HTF/]
[Isakowitz 1993]< TomĚs Isakowitz. "Hypermedia in Information Systems and Organizations: A Research Agenda," Proceedings of Twenty-Sixth Annual Hawaii International Conference on System Science (HICSS) (Maui, Jan. 1993), Volume III, pages 361-369.
[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.
[Kuutti 1998]< Kari Kuutti (editor). Proceedings of the Seventh International Workshop on Hypertext Functionality: Organizational Memory Systems and HTF, Helsinki ,1998.
[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.
[Nürnberg 1998]< Peter J. Nürnberg, John J. Leggett, and Uffe K. Wiil, "An Agenda for Open Hypermedia Research" in Proceedings of ACM Hypertext '98, Pittsburgh, PA, 198-206, [Online: http://acm.org/pubs/citations/proceedings/hypertext/276627/p198-nurnberg/], June 1998.
[Noll 1996]< John Noll and Walt Scacchi. "Repository support for the virtual software enterprise" in Proceedings of the Second International Workshop on Incorporating Hypertext Functionality Into Software Systems (HTF II), Helen Ashman, V. Balasubramanian, Michael Bieber, and Harri Oinas-Kukkonen (editors), ACM Hypertext '96 Conference, Washington DC, March 1996.
[Noll 1999]< John Noll and Walt Scacchi. "Supporting Software Development in Virtual Enterprises" in Journal of Digital Information 4, [Online: http://jodi.ecs.soton.ac.uk/Articles/v01/i04/Noll], 1999.
[OHS 1999]< Open Hypermedia Systems Homepage [on-line: http://www.csdl.tamu.edu/ohs/]
[Oinas-Kukkonen 1995]< Harri Oinas-Kukkonen. "Developing Hypermedia Systems ? the Functionality Approach" in Proceedings of the Second Basque International Workshop on Information Technology (BIWIT ╠95), keynote address, IEEE Computer Society Press, Los Alamitos, CA, 2-8, 1995.
[Oinas-Kukkonen 2000]< Harri Oinas-Kukkonen. "Flexible CASE and Hypertext" in ACM Computing Surveys Symposium on Hypertext and Hypermedia, 2000.
[Puttress 1990]< J. J. Puttress and N. M. Guimaraes. "The Toolkit Approach to Hypermedia"in Proceedings of the ACM European Conference on Hypertext '90 (ECHT '90), Versailles, France, 25-37, November 1990.
[Schnase 1989]< John L. Schnase and John J. Leggett. "Computational Hypertext in Biological Modelling," in Proceedings of ACM Hypertext '89, Pittsburgh, PA, Pittsburgh, PA, 181-198, November 1989.
[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.
[Selvin 1999]< Albert M. Selvin. "Supporting Collaborative Analysis and Design with Hypertext Functionality" in Journal of Digital Information 4, [on-line: http://jodi.ecs.soton.ac.uk/Articles/v01/i04/Selvin - note: requires password], 1999.
[Sherman 1990]< Mark Sherman, Wilfred J. Hansen, Michael McInerny, and Thomas Neuendorfer. "Building Hypertext on a Multimedia Toolkit: An Overview of the Andrew Toolkit Hypermedia Facilities"in Proceedings of the ACM European Conference on Hypertext '90 (ECHT '90), Versailles, France, 13-24, November 1990.
[Thüring 1995]< Manfred Thüring, Jörg Hannemann, and Jörg M. Haake. "Hypermedia and cognition: designing for comprehension" in Communications of the ACM (CACM), 38(8), 57-66, August 1995.
[Whitehead 1997]< E. James Whitehead, Jr. "An Architectural Model for Application Integration in Open Hypermedia Environments" in Proceedings of ACM Hypertext '97, Southampton, UK, 1-12, April 1997.
[Wiil 1999]< Uffe K. Wiil. "Overview of Workshop Discussions", Proceedings of the Fifth Workshop on Open Hypermedia Systems, ACM Hypertext '99 Conference, Technical Report CS-99-01, Aalborg University, Denmark [on-line: http://www.aue.auc.dk/~kock/OHS-HT99/ohs5.pdf], February 1999.
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