T.H. Nelson proposes the development of the Evolutionary List File (ELF), a file structure characterized by “the capacity for intricate and idiosyncratic arrangements, total modifiability, undecided alternatives, and thorough internal documentation” (84). Built of zippered files, the ELF would fulfill user needs for personal filing and manuscript assembly. Among the ELF’s specifications are “the ability to accept large and growing bodies of text and commentary,” the ability to “file texts in any form and arrangement desired…under an unlimited number of categories, allowing “index manipulations” known as “dynamic indexing” and permitting evolutionary “dynamic outlining” (88).
Nelson characterizes the ELF as an evolutionary file structure which “can be shaped into various forms, [and] changed from one arrangement to another in accordance with the user’s changing needs” (89). Stressing simplicity, Nelson’s system contains three elements: entries, lists, and links. An entry is a unit of information, such as text or pictures; a list is an ordered set of entries; and a link is a bridge between different entries in different lists (89-90). In regards to the ELF’s file operations, Nelson states that the ELF must be “though of as a place; not a machine, but a piece of stationary or office equipment with many little locations which may be rearranged with regard to one another” (91). In regards to the technical aspects of the ELF, it is designed to “be changed piecemeal by a human individual,” as opposed to pre-existing list languages which process data too quickly for human input.
Nelson explores the potential uses for the ELF system, among which are a “glorified card file,” (92) and a system useful to writers in that it enables “self-documentation” (93). Nelson also introduces the Personalized Retrieval, Indexing, and Documentation Evolutionary System (PRIDE), an information handling language whose purpose it is to facilitate ELF usage (94).
In Nelson’s system links to philosophy, he introduces the concept of hypertext, which he defines as “a body of written or pictorial material interconnected in such a complex way that it could not conveniently be presented or represented on paper,” and “may congaing summaries, or maps of its contents and their interrelations; it may contain annotations, additions and footnotes from scholars who have examined it” (96). He suggests that the ELF is such a system which would enable the use of hypertext in a user-controlled, non-hierarchical domain.
Nelson, T.H. “A File Structure for The Complex, The Changing and the Indeterminate.” Complex Information Processing. ACM 20th National COnference. 24 Aug 1965. Address.