An encyclopedia (alternatively "encyclopaedia") is a written compendium of human knowledge. Encyclopedias can be generalist, containing articles on topics in all fields, or they can specialise in one particular field (e.g. an encyclopedia of medicine or philosophy).
Many writers of antiquity (such as Aristotle) attempted to write comprehensively about all human knowledge. However, John Harris is often credited with establishing the now-familiar encyclopedia format in 1704 with his Lexicon technicum. The venerable Encyclopaedia Britannica had a modest beginning: from 1768 to 1771 three volumes were published. Perhaps the most famous early encylopedia was the French Encyclopédie, edited by Jean Baptiste le Rond d'Alembert and Denis Diderot and completed in 1772.
The encyclopedia's hierarchical structure and evolving nature is particularly adaptable to a disk-based or on-line computer format, and all major printed encyclopedias have moved to this method of delivery in recent years. Disk-based (typically CD-ROM format) publications have the advantage of being cheaply produced and extremely portable. Additionally, they can include media which is impossible in the printed format, such as animations, audio and video. Hyperlinking between conceptually related items is also a significant benefit. On-line encyclopedias offer the additional advantage of being (potentially) dynamic: new information can be presented almost immediately, rather than waiting for the next release of a static format (as with a disk or paper based publication).
Information in a printed encyclopedia necessarily needs some form of hierarchical structure, and traditionally the method employed is to present the information ordered alphabetically by the article title. However with the advent of dynamic electronic formats the need to impose a pre-determined structure is unnecessary. Nonetheless, most electronic encyclopedias still offer a range of organisational strategies for the articles, such as by subject area or alphabetically.
- History of Science and Technology
- Library and Information Science
- Lexicography and dictionaries
Commercial online general encyclopedias
- Columbia Concise
- Grolier (subscription fee required)
- Encyclopaedia Britannica (subscription fee required for full access; free trial available)
- Microsoft Encarta
- World Book (subscription fee required; free trial available)
Encyclopedia projects, free and not
Links to encyclopedias
- An enormous list of links to dictionaries and encyclopedias (last updated Nov. 1999)
- cnet's encyclopedia metasearch page, which includes Wikipedia