Untitled - witz cultural

24HYPERTEXT 3.0 ever created a link in HTML that point seems obvious, and, in fact, placinglinks within each lexia has major benefits, including simplicity, ease ofcreating them, and permanence-they dont move or get lost. This conceptionof the link, however, represents a fundamental deparhrre from the kindof medium proposed by Vannevar Bush. The user of the memex, we recall,created trails of associative links on top of already existing texts, saved thosetrails, and shared them with others. Different readers could create very differentcollections of links for the same texts. Links, in other words, exist outsidethe individual lexia in this kind of hypermedia.Many hlpertext researchers, inspired by Bush, have designed and implementedsuch open hypermedia systems and infrastructures, a defining characteristicof which is the link database or linkbase (see Rizk and Sutcliffe fora list of such systems). Intermedia, one such system, drew upon its separationof links and data to permit users to generate multiple webs from the samebody oftexts and images; depending on an individual userk access rights, heor she could view the webs created by others. In educational terms, using alinkbase had the effect of permitting students to use the main course web pluslinks added by students or to screen out links created by them. It also permittedinstructors, as we shall see in chapter 4, to use links to incorporate materialscreated by those in other disciplines within their webs without affectingeither the original author's text or web. In practice, readers experiencedan Intermedia web, such as Context32, much as they do its HTML descendant,The Viaorian Web.Infact, each hypermedia collection of documents existedonly as a virfual web called into being by the linkbase and linkserver.The linkbase and its associated server, which combine to create link services,lie at the heart of open hypermedia systems like Hyperbase, Multicard,Sun's Link Service, Microcosm, and its various later incarnations. David C.De Roure, Nigel G. Walker, and Leslie A. Carr offer the following definitionof these key terms:At its simplest, a hypermedia link servertakes a source anchor in a multimedia documentand returns the possible destination anchors, obtained by interrogating a linkdatabase (henceforth a linkbase) for links containing that anchor. The anchors mightidentify specific locations or objects in particular multimedia documents; alternativelythey might have broader applicability, matching content rather than position(so-called genericlinking). The linkbase query might also be refined by the user's context,perhaps based on their profile, current role, task and location. Link services maybe accessed before, during or after document delivery, and they may provide an interfacefor link creation and maintenance as well as retrieval. (67)