Encyclopedia of Computer Science and Technology

234 hypertext and hypermediaImplementationA hypertext document consists of nodes. A node can be apart of a document that conveys a logical “chunk” of information,such as the text that would be under a particularheading in a traditional document. In some systems nodescan be grouped together as a composite—for example, thesecond-level headings under a first-level heading might beconsidered nodes making up a single composite.The text contains links. A link specifies an anchor orspecific location to which it points. The user normallydoesn’t see the anchor, but rather the marker, which issome form of highlighting (such as a different color) thatindicates that an area is a link that can be clicked on.(In systems such as the Web, link markers need not betextual. Small pictures are often used as visual link markers.)Web browsers and other hypertext programs oftensupplement the use of links with various navigation aids.These can include buttons for traversing back or forwardthrough a list of recently visited links, a history list fromwhich previous links can be selected, and bookmarks thatallow the user to save and descriptively label importantlinks for easier future access.Hypertext is becoming the dominant paradigm for presentingtechnical or other reference information. With lessstructuredtext, hypertext links are usually considered to besupplemental to the traditional structure. The term hypermediarefers to the linking of nontextual material—images,videos, sound files, even Java applets and other programs.(Since both hypertext and hypermedia are now so ubiquitous,the terms themselves seem to be used less frequentlyexcept in an academic context.)Hypertext perhaps achieves its fullest power when itis used for collaborative expression and research. Withoutbeing able to easily link to what is being discussed, blogswould just be static diaries (see blogs and blogging).Wikis, too, depend on linking not only to reference existing,related entries, but to “grow” the tree of knowledgewith “stubs” being put in to encourage other contributors toflesh out related topics (see wikis and Wikipedia). Despitesuggestions to the contrary, hypertext seems to be problematicwith regard to fiction, unless a work is constructed asan explicit hypertext. If hypertext literature becomes popular,it will require that both authors and readers radicallychange their role and expectations with regard to the text.Further ReadingBromme, Rainer, and Elmar Stahl. Writing Hypertext and Learning.Kidlington, Oxford, U.K.: Elsevier Science, 2002.Bush, Vannevar. “As We May Think.” Atlantic Monthly 176, 101–108. Available online. URL: http://www.theatlantic.com/doc/194507/bush.Landow, George P. Hypertext 3.0: Critical Theory and New Mediain an Era of Globalization. 3rd ed. Baltimore: Johns HopkinsUniversity Press, 2006.McCann, Jerome. Radiant Textuality: Literature after the WorldWide Web. New York: Palgrave Macmillan, 2001.Nelson, Theodore. Computer Lib/Dream Machines. Rev. ed. Chicago:Hugo’s Books, 1987.Snyder, I. Hypertext: the Electronic Labyrinth. New York: New YorkUniversity Press, 1997.