How confident are you that you know pretty much everything? Of course, there are differences between "need to know," "have to know," "nice to know," and "happen to know." But pick up any dictionary and you will likely encounter information you used to know, information that's nice to know, and information you'd just as soon ignore, as well as information your already know (at least in part). So, what is an encyclopedia?
The definition quoted above would be more precise if it described encyclopedias as repositories containing a systematic overview and select summary of human knowledge. Through definitions, brief and extended essays, and cross-references, encyclopedias intend to inform and educate the average person about something with which he or she may be unfamiliar. Jacques Barzun, a noted scholar, defined encyclopedias more narrowly (and somewhat cynically) as primarily works of "reference," whose main purpose is to answer questions of fact and meaning. Barzun described how encyclopedias are used innappropriately by most students. Many instructors at all levels have adopted Barzun's definition and fearful that many students will go no further have discouraged encyclopedia use in research.
However, beyond the factual information and data that by definition they include, encyclopedias provide an appropriate and useful beginning point for novice researchers. Encyclopedias consist of essays of varying length, researched and written by content specialists who place a topic within a context and through cross-references show the interdisciplinarity of subjects and the interrelationships of people, places, concepts, events, and things. Encyclopedias often include maps, statistics, and illustrations. While not all encyclopedias include them, bibliographies with many essays direct a user to more in-depth or primary resources. These aspects often provide students and novice researchers with sufficient background information to better define a research project or the scope of what is to be learned.
There are several ways to charaterize encyclopedias. Most commonly found are general, usually multi-volume, encyclopedias; World Book or Encyclopaedia Britannica are widely available in libraries; in turn, general encyclopedias may be directed by their reading level to a specific audience, like children's encyclopedias. Specialized encyclopedias come in a variety of "flavors:" covering a specific field (e.g., medicine or philosophy), or a national, cultural, or ethnic group (e.g., Encyclopaedia Judaica), or a specific topic that may cross several subjects (e.g., Encyclopedia of World War II). Encyclopedias are typically organized alphabetically, but some are organized by some unique topical hierarchy used only by that one title; electronic encyclopedias allow for new possibilities of organization and, with linking capabilities, a more integrated access to interdisciplinary content.
In the halcyon days of door-to-door sales, less than 50 years ago, more than 400,000 print sets of World Book were sold to families each year; now there are less than 100,000 print volumes sold, with most going to schools and libraries. The earliest electronic encyclopedias, such as the Grolier Multimedia Encyclopedia, were published as CD-ROMs and frequently bundled with home computers; most parents who could afford a print encyclopedia prefered to purchase a personal computer, especially when the computer came with an encyclopedia on CD. The advent of the Web provided new opportunities for distribution, but initially did little to change the content. The development and expansion of Encarta, which grew from a Funk & Wagnalls New World Encyclopedia foundation, included multimedia add-ons, such as maps, audio and video clips, and interactive graphics, as well as hypertext linking. The Encyclopaedia Britannica, while still available in print, is available online, although access to complete articles often requires a subscription. More recent online encyclopedias, like Wikipedia or h2g2 are largely built by users, far easier to search, and can be dynamic, responding to changes almost as fast as they occur.
The largest encyclopedia ever produced was the Great Yongle Encyclopedia (Yongle Dadian), commissioned during the Ming Dynasty and running to 11,095 hand-printed volumes--of which only 400 remain. The Encyclopaedia Britannica is the oldest and historically most respected English-language encyclopedia. Wikipedia, the popular and controversial online encyclopedia, had more than 1.8 million articles in its English-language edition as of May 2007; there are 252 different language editions of Wikipedia, with the English edition accounting for 51% of total Wikipedia use. In general, Wikipedia is extremely popular (see, for example, the Pew/Internet Data Memo on Wikipedia Users), but challenges librarians, teachers, and users to verify content and authorship, as well as presentation and persistence; Middlebury College has gone so far as to ban the use of Wikipedia in preparing class papers. The policy says "Wikipedia is not an acceptable citation, even though it may lead on to a citable source;" like any encyclopedia, Wikipedia is a decent place to start research but an unacceptable way to end it. For more on the Wikipedia controversy, see the Wikipedia article Criticism of Wikipedia.
