Looking for Patterns
This paper describes a variety of patterns of linkage observed in actual hypertexts. Hypertext structure does not reside exclusively in the topology of links nor in the language of individual nodes, and so we must work toward a pattern language through both topological and rhetorical observation. Instances of these patterns typically range in scope from a handful of nodes and links to a few hundred. These patterns  are components observed within hypertexts, rather than system facilities (see ) or plans of a complete work. Typical hypertexts contain instances of many different patterns, and often a single node or link may participate in several intersecting structures.
I do not argue that the observed structural patterns are uniquely desirable, that superior patterns cannot be devised, or indeed that the writers of these hypertexts meant to use these patterns at all. I do propose that by considering these patterns, or patterns like them, writers and editors may be led to more thoughtful, systematic, and sophisticated designs. These patterns are offered, then, as a step toward developing a richer vocabulary of hypertext structure. Examples are drawn from published stand-alone hypertexts as well as from the Web. Web sites are readily accessible but volatile: a site which today illustrates one structure may be unrecognizable tomorrow. Published hypertexts are less accessible, but are also more permanent. Moreover, some important patterns depend on dynamic links -- links which depend on the reader's past interactions. The Web itself is state-free, and while various implementations of state-dependent behaviors for the Web have been proposed, state-dependent behavior remains an exceptional case in Web hypertexts.
Some pattern examples are drawn from literary fiction. I do not believe these patterns to be useful exclusively for fiction; rather, a variety of economic and cultural factors sometimes encourage experimentation in narrative rather than technical writing or journalism. Moreover, hypertext fiction tends to be written for general audiences and may remain available indefinitely, while specialized reference manuals and Help systems may be short-lived and less readily available to the general reader. Nor does our interest in structural vocabulary necessarily imply a structuralist or post-structuralist stance; we need to describe phenomena, whatever our theoretical beliefs . Two patterns -- Tree and Sequence -- have been described many times in the hypertext literature . Both are useful, indeed indispensable, and can be found in almost any hypertext.
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