This volume, which the editors have divided into sections on the creation, extension, and legacy of the Memex, combines seven essays by the man credited with envisioning hypertext with eleven others by others that set his ideas within a variety of contexts. The essays by Bush range chronologically from the early "The Inscrutable Thirties" (1933), "Memorandum Regarding Memex" (1941), and "As We May Think" (1945) -- the single work for which most students of hypertext know its author -- to "Memex II" (1959), "Science Pauses" (1967), "Memex Revisited" (1967), and a passage from "Of Inventions and Inventors" (1970). Nyce and Kahn surround Bush's essays by four chapters that place his changing plans for the Memex within his career and within information technology before digital computing.
In his detailed and heavily illustrated "Vannevar Bush and the Differential Analyzer: The Text and Context of an Early Computer," Larry Owens clearly, if dryly, tells the story of Bush's work on an elaborate mechanical analogue computer. In the chapter that follows, "A Machine for the Mind: Vannevar Bush's Memex," the editors themselves set the Memex within the context of the MIT Rapid Selector, an information retrieval machine based on microfilm technology (about which Colin Burke provides another chapter). Setting the Memex within the context of speculative scientific utopian fiction, Nyce and Kahn also trace the long path of Bush's famous article to print. Their fascinating piece, which is packed with information, reveals that Bush conceived the Memex almost a decade and a half before he published "As We May Think!" The editors' second chapter traces the development of Bush's conceptions of the Memex from "a memory extender" (122) to an intellectual symbiot. Bush, who in later years increasingly approached conceptions of machine thinking found in cyberpunk novelists like Rudy Rucker, nonetheless at the end pulled back from a full identification of man and machine, and he did so as a means, the editors argue, of "defending against materialism" (135).
The final section of the volume, entitled "The Legacy of Memex," contains important contributions by pioneers of this new information technology. From Douglas Englebart, the man who invented the computer mouse and the first true working hypertext system, we have his letter to Bush of May 14, 1962 in which he describes a program he was trying to start at the Stanford Research Institute and also his "Program on Human Effectiveness," which sets forth these plans for "an integrated man-machine working relationship, where close, continuous interaction with a computer avails the human of radically changed information-handling and -portrayal skills, and where clever utilization of these skills provides radical changes in the way the human attacks problems" (237). Immediately after Englebart's contributions, the editors have placed a key essay by the third of the hypertext trinity -- Theodor H. Nelson, the originator of the term hypertext. His chapter, a reprint of "As We Will Think" (1972), makes the point that the famous call for the Memex has been "generally misinterpreted, for it has little to do with Ćinformation retrieval' as prosecuted today. Bush rejected indexing and discussed instead new forms of interwoven documents" (245).
Nyce and Kahn have also included essays by Norman Meyrowitz, Tim Oren, Gregory Crane, and Randall H. Trigg. In his chapter, characteristically entitled "Hypertext -- Does It Reduce Cholesterol, Too?" Meyrowitz, one of the lead members of the team that created IRIS Intermedia, combines a vision of hypertext as far reaching as any with a level-headed assessment of what has thus far been achieved and what yet remains to be done. He points out that "Down deep, we all think and believe that hypertext is a vision that sometime soon there will be an infrastructure, national and international, that supports a network and community of knowledge linking together myriad types of information for an enormous variety of audiences" (288). Proposing a plan for the Desktop of Tomorrow and another for hypertext in general, he lists a large number of essential requirements including (a) active anchors, (b) virtual, automatic, navigational, warm, and hot links, (c) wayfinding, (d) user histories, (e) filtering, (f) queries, and (g) semantic markup. He ends with a list of fourteen challenges, the last of which is for all the major vendors of hard and software include in their products application-independent linking protocols.
After Meyrowitz's stirring blend of the visionary and the practical (or at least an enumeration of the steps we must take to fulfill Bush's now-expanded vision) the editors provide an emotional swerve with the inclusion of Linda C. Smith's "Memex as an Image of Potentiality Revisited." Before any of us finds ourselves tempted to make outlandish claims about Bush's far-reaching influence -- or about that of any other person, idea, or technology -- we might do well to consult Smith's study of the way Bush has been used by other authors on information technology. Using citation indexes, she has classified mentions of Bush into five categories: "1) historical perspective; 2) hardware; 3) information store; 4) association and selection,; [and] 5) personal information system." (263). Few of these many citations, it turns out, show much comprehension of Bush's vision. Simply put, Smith shows that many who have cited Bush and the Memex have done so on account of his trendiness and often with little understanding, or even knowledge, of what he had proposed.
She also points out that Bush's notions of trails and paths have recently received special attention, and amost all the essays that follow point to the truth of Child's observation. With the exception of Gregory Crane, who discusses Project Perseus, the remaining essays propose to discuss and advance Bush's legacy by concentrating, not on links but on paths. Here all seem to be following the lead of Polly Zellweger, whose talk, "Scripted Documents: A Hypermedia Path Mechanism," at Hypertext Ć89 has made many look freshly at Bush's ideas. Most of us who work with hypertext tend to think of it in Ted Nelson's terms as electronic text composed of nodes and links meant to read non- (or multi-) sequentially. Bush, in contrast, thought of the Memex chiefly in terms of trails through t hese links and nodes. As Randall H. Trigg argues, "one critical feature of Bush's original notion of trailblazing has yet to be realized, namely, the subsumption of linking under the activities of trail creation and following, or more simply, linking as trailblazing" (353). Trigg correctly points out that in Bush's vision of the Memex, links primarily embodied, not relationships between node and node, but meaningful sequences.
Although Ted Nelson's 1972 piece mentions paths, it quickly turns from them to the freer, even anarchic vision of hypertext for which he is known. According to him, "In Bush's trails, the user had no choices to make as he moved through the sequence of items, except at an intersection of trails. With computer storage, however, no sequence need be imposed on the material; and, instead of simply storing materials in their order of arrival or of being noticed, it will be possible to create overall structures of greater useful complexity" (253). Most recent authors on hypertext have further emphasized its creation of multilinear textuality. Many, including Nelson and Meyrowitz, have also stressed its reconfiguration of readers as reader-authors (or in the term I have recently come upon on the computer conference "Technoculture," wreaders).
Meyrowitz, one of the authors of "Reading and Writing the Electronic Book," a well known article that proposed blurring the roles of readers and writers, also discusses trails and paths in his chapter in this volume. According to him, "Paths are essentially histories that have been captured, edited, shortened, and made into concrete desktop objects that can be played back again. . . . We'd like users not to have to program these paths but to be able to create them by actually doing the traversals and editing out events that they don't necessarily want to keep" (304). As this passage suggests, Meyrowitz here combines his earlier emphasis on Nelsonian form of hypertextuality with after-the-fact trails.
Tim Oren takes a different tack. His "Memex: Getting Back on the Trail," which begins with the statement that "the notion of a trail, or sequence of associations, is central to Bush's vision of the Memex" (319), emphasizes that Bush's notions evolved from a machine whose chief benefit lay in the fact that its memory paths do not fade to one that could learn and adapt, and this, he claims, anticipates his own notions of how one interact with fully realized hypertext systems. "In the adaptive Memex, the owner's trails are to be mutable, with the possibility of change and fresh creation by the Memex itself." Here the Memex, Oren claims, acts as "what has been termed an Ćagent'" (324), and he explains how this "possibility of change in the user's absence" (326) changes our usual assumptions about computing. Oren, who has done pioneering work on agents, looks at the problems and promises created by dynamic information, individual and adaptive databases, heterogeneous information, and user modeling.
Oscar Wilde once accused the poet William Wordsworth of finding sermons in stones that he had previously hidden there himself, and one might be tempted to make similar charges against many who claim to draw upon Bush for inspiration. Certainly, as Child so convincingly demonstrates, readers of Bush's writings on the Memex have tended to find all their own ideas and emphases confirmed by it. But as Oren's essay also suggests, leading workers in hypertext find varying inspirations and emphases as they encounter varying problems in the fulfillment of Bush's vision.
The authors of this well conceived volume are to be congratulated for so effectively presenting the ideas and heritage of Vannevar Bush, a very practical engineer and scientific administrator who had some very impractical visions of the ways we may think.
To George P. Landow, Reviews