The other is text retrieval, which allows associations to be deduced from the content of text. The W 3 ideal world allows both operations and provides access from any browsing platform. Various server gateways to other information systems have been produced, and the total amount of information available on the web is becoming very significant, especially since it includes all anonymous FTP archives, WAIS servers, and Gopher servers as well as specific W 3 servers.
The paper notices that a W 3 server could provide the functions of each of these servers, and so it looks forward to a single protocol that can be used by the whole community. Emerald Group Publishing Limited. Report bugs here. Please share your general feedback. Conventional distributed hypermedia systems suf fer from some well-known problems that make effective, goal-directed document retrieval and maintenance impossible.
Relationships between documents are … Expand. View 1 excerpt, cites methods. Prospero: a tool for organizing Internet resources. Internet Res. Recent growth of the Internet has greatly increased the amount of information that is accessible and the number of resources that are available to users. To exploit this growth, it must be possible … Expand. View 3 excerpts, references background and methods. The Dexter Hypertext Reference Model. View 1 excerpt, references methods.
Network news transfer protocol a proposed standard for the stream-based transmission of news. Business, Computer Science. View 2 excerpts, references methods. Knowledge-based client-server approach to structural information retrieval: the Digital Anatomist Browser. Computer Science, Medicine. Computer methods and programs in biomedicine. File Transfer Protocol. As we may think. Political Science, Computer Science. The client is therefore prepared to follow several stages of translation by name servers before finding a final document server.
Similarly, a document name should not contain any information which is transitory such as the particular formats available for a document, or its length, for example. The W3 naming scheme fulfills these requirements, but is otherwise open to the addition of new protocols as technology evolves. For this purpose a prefix is used to identify the protocol and therefore naming scheme to be used.
Clients which do not have that protocol in their repertoire refer to a gateway for translation. Protocols The W3 clients are built on a common core of networking code for information access. A new search and retrieve protocol was found necessary, known as HTTP.
Faster than FTP for document retrieval, this also allows index search. Some differences are discussed below. Document Formats The Dexter data model of hypertext [11] provided a conceptual model for hypertext systems, and the HyTime standard [12] formalizes hypertext at a high level.
The W3 project defines a concrete syntax in the SGML style for basic hypertext as used for menus, search results, and on-line hypertext documentation. Every W3 browsing application is able to parse this simple format see Fig. In the pilot phase of the project, this format was all that was required, but in the second phase, format negotiation between client and server will allow the exchange of information in any medium using any mutually acceptable representation.
In this way, WAIS indexes and servers can be represented in the web. A gateway program, running at CERN and available for general use, provides this mapping. The link is represented in the winodw by underlining, on the terminal by a reference number. The current WAIS model requires that the results of a search point to documents available from the same server. That is, the same server is responsible for indexing and actually providing the data. In the W 3 world this restriction does not exist.
It is expected that these services will be a key to the control of the information explosion, and a valuable asset to the community. A W3 user builds a personalized web of information by making links from his own notebook into the web. He can make a link to the result of performing a search, such that next time he follows the link the search is reevaluated. The W 3 clients do not currently support relevance feedback although it is not alien to the model.
There are two occasions when hypertext would particularly enhance the WAIS model. Firstly, users often would like to be able to browse through available WAIS indexes. WAIS and W3 both regard indexes as documents, and therefore allow them to be found using the same techniques as for documents. Secondly, when one has found a piece of text, WAIS delivers just that part of a file which has been found. Very often one would like links to surrounding information in the same database.
The popularity of WAIS has been a great boost to the world of online information. Its integration with universal naming and hypertext is to be greatly encouraged. Menu systems and The Web The Alex[5], Internet Gopher[6] and Prospero[7] systems each use the directory and file or menu and document model to implement a global information system.
These map into the web very naturally, as each directory menu is represented by a list of text elements linked to other directories or files documents. These systems are very comfortable for readers who are used to hierarchical file systems, for whom directories are an established concept.
Even when the structure is in fact cross-linked, the reader feels at home as he regards it as a tree structure. Furthermore, for the information provider such systems are easy to build by cross-linking existing file systems.
An example of mapping a menu system onto the web is made by the W3 client software which incorporates the simple Gopher protocol, and therefore allows links into the Gopher system. The easy start-up of these systems has made them fairly popular. It is true that a menu is necessarily a more restricting medium of communication than general hypertext: a page of hypertext can convey more information to the reader about the choices to be followed, by using more flexible formatting.
Hypertext allows menus of links to lead to nodes with progressively greater textual content. However, the restricted world of plain text and menus, with its ease of publication, is adequate for many information providers. Initially intended for coordinates of people and organizations, to be used for documents it needs extensions similar to though simpler than those proposed for example by Yeong [14].
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