Randall H. Trigg's Ph.D. Thesis at the University of Maryland.
"The thesis focuses on specific link types that support literary criticism."
Textnet implements two basic types of nodes; those which have textual content (chunks) and those which hierarchically organize other nodes (tocs, for "table of contents"). Thus Textnet supports both hierarchical trees (via the toc nodes) and nonhierarchical graphs (via the typed links).
Trigg further proposes a specific taxonomy of link types for use by collaborators and critics in Textnet. He argues that there is generally a specific set of types of comments, and that there is a link type for each comment. For example, there are refutation and support links, and , more specifically, there are links to say that a point is irrelevant ("Pt-irrelevant"), that data cited is inadequate ("D-inadequate"), or that the style is rambling ("S-rambling"). Trigg describe over 80 such link types and argues that the disadvantage of having a limited set of link types is outweighed by the possiblity of specialized processing on the hyperdocument afforded by a definitie and fixed set of primitives.
In addition, Textnet supports the definition of pats-ordered lists of nodes used to browse linear concatenations of text and to dump such scans to hard copy. The path facility relieves the hypertext reader from having to make an n-way decision at every link; rather, the reader is provided a default pathway through the network (or part of the network), and can simply read the material in the suggested order as if he were reading a linear document. Trigg joined Xerox PARC after completing his thesis and was on of the principal architects of the Xerox NoteCards system.
(Conklin, 1987)