computer science

Wide Area Information Server

Wide Area Information Server is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Wide Area Information Server rather than just read about it. In short: Wide Area Information Server (WAIS) is a client–server text searching system that uses the ANSI Standard Z39.50 Information Retrieval Service Definition and Protocol Specifications for Library Applications" (Z39.50:1988) to search index databases on remote computers. It was developed in 1990 as a project of Thinking Machines, Apple Computer, Dow Jones, and KPMG Peat Marwick.

Key takeaways

Wide Area Information Server belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Wide Area Information Server to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Wide Area Information Server from memory before moving on to harder problems.

Reference excerpt

Wide Area Information Server (WAIS) is a client–server text searching system that uses the ANSI Standard Z39.50 Information Retrieval Service Definition and Protocol Specifications for Library Applications" (Z39.50:1988) to search index databases on remote computers. It was developed in 1990 as a project of Thinking Machines, Apple Computer, Dow Jones, and KPMG Peat Marwick. WAIS did not adhere to either the Z39.50 standard nor its OSI framework, adopting instead TCP/IP. It created a unique protocol inspired by Z39.50:1988.

History The WAIS protocol and servers were promoted by Thinking Machines Corporation (TMC) of Cambridge, Massachusetts. TMC-produced WAIS servers ran on their massively parallel CM-2 (Connection Machine) and SPARC-based CM-5 MP supercomputers. WAIS clients were developed for various operating systems and windowing systems including Microsoft Windows, Macintosh, NeXT, X, GNU Emacs, and character terminals. TMC released a free open source software version of WAIS for Unix in 1991. Inspired by the WAIS project on full-text databases and emerging SGML projects, Z39.50 version 2 (Z39.50:1992) was released. Unlike its 1988 predecessor, it was a compatible superset of the international ISO 10162/10163 standard. With the advent of Z39.50:1992, the termination of support for free WAIS by Thinking Machines and the establishment of WAIS Inc as a commercial venture, the U.S. National Science Foundation funded the Clearinghouse for Networked Information Discovery and Retrieval (CNIDR) to promote Internet search and discovery systems, open source and standards. CNIDR created a new, free open-source WAIS. This was the first freeWAIS based on the wais-8-b5 codebase of TMC, with a wholly new software suite Isite based upon Z39.50:1992 using Isearch as its full-text search engine. Ulrich Pfeifer and Norbert Gövert of the computer science department of the University of Dortmund extended the CNIDR freeWAIS code to become freeWAIS-sf with structured fields as its main improvement. Ulrich Pfeifer rewrote freeWAIS-sf in Perl, becoming WAIT. Inspired by WAIS' "Directory of Servers", Eliot Christian of USGS envisioned GILS: Government Information Locator Service. GILS (based upon Z39.50:1992 with some extensions) became a U.S. Federal mandate as part of the Paperwork Reduction Act of 1995 (44 U.S.C. § 3511).

Directory of Servers Thinking Machines Corp provided a service called the Directory of Servers. It was a WAIS server like any other information source except containing information about the other WAIS servers on the Internet. A WAIS server with TMC WAIS code creates a special record containing metadata plus some common words describing its indexed content. The record is uploaded to the central server and indexed along with the records from other public servers. The directory can be searched to find servers that might have content relevant to a specific field of interest. This model of searching for (WAIS) servers to search became the model for GILS and Peter Deutsch's WHOIS++ distributed white pages directory.

People Two of the developers of WAIS, Brewster Kahle and Harry Morris, left Thinking Machines to found WAIS Inc in Menlo Park, California, with Bruce Gilliat. WAIS Inc. was originally a joint project between Apple Computer, Peat Marwick, Dow Jones, and Thinking Machines. In 1992, the presidential campaign of Ross Perot used the WAIS product as a campaign-wide information system, connecting the field offices to the national office. Later, Perot Systems adopted WAIS to better access the information in its corporate databases. Other early clients were the Environmental Protection Agency, Library of Congress, and the Department of Energy and later the Wall Street Journal and Encyclopædia Britannica. WAIS Inc was sold to AOL in May 1995 for $15 million. Following the sale, Margaret St. Pierre left WAIS Inc to start Blue Angel Technologies. Her WAIS variant formed the basis of MetaStar. Georgios Papadopoulos left to found Atypon. François Schiettecatte left Human Genome Project at Johns Hopkins Hospital and started FS-Consult and developed his own variant of WAIS which eventually became ScienceServer, which was later sold to Elsevier Science. Kahle and Gilliat went on to found the Internet Archive and Alexa Internet.

WAIS and Gopher Public WAIS is often used as a full-text search engine for individual Internet Gopher servers, supplementing the popular Veronica system which only searches the menu titles of Gopher sites. WAIS and Gopher share the World Wide Web's client–server architecture and a certain amount of its functionality. The WAIS protocol is influenced largely by the z39.50 protocol designed for networking library catalogs. It allows a text-based search, and retrieval following a search. Gopher provides a free text search mechanism, but principally uses menus. A menu is a list of titles, from which the user may pick one. While Gopher Space is a web containing many loops, the menu system gives the user the impression of a tree. The Web's data model is similar to the gopher model, except that menus are generalized to hypertext documents. In both cases, simple file servers generate the menus or hypertext directly from the file structure of a server. The Web's hypertext model permits the author more freedom to communicate the options available to the reader, as it can include headings and various forms of list structure.

See also Timeline of the history of the Internet

References

External links Wide Area Information Servers (WAIS) launch lecture (Xerox PARC, 1991) RFC1625: WAIS over Z39.50-1988 M. St. Pierre, J. Fullton, K. Gamiel, J. Goldman, B. Kahle, J. Kunze, H. Morris, F. Schiettecatte, June 1994 RFC 4156: The wais URI Scheme P. Hoffman, August 2005 The Z39.50 Information Retrieval Standard Part I: A Strategic View of Its Past, Present and Future, Clifford A. Lynch, D-Lib Magazine, April 1997 Usage of WHOIS through the swais command: "EFF's (Extended) Guide to the Internet - Wide-Area Information Servers". www2.cs.duke.edu. 1994. Retrieved 2020-01-26.

Worked examples

Example 1 — a first encounter with Wide Area Information Server

Start with the simplest possible case. Write down what Wide Area Information Server claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Wide Area Information Server before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Wide Area Information Server ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Wide Area Information Server

In research: Wide Area Information Server appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Wide Area Information Server in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Wide Area Information Server is common in secondary-school and first-year university syllabi. It links to neighbouring topics Gopher (protocol), Internet Standards, Internet protocols, so understanding it makes those chapters shorter.
In everyday life: Look for Wide Area Information Server outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Wide Area Information Server in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Wide Area Information Server means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Wide Area Information Server out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Wide Area Information Server in simple terms?

Why does Wide Area Information Server matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Wide Area Information Server?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Wide Area Information Server.