The printed encyclopedia
For roughly two centuries, a general encyclopedia meant a multivolume printed set. Teams of editors commissioned articles from specialists, and the finished work was sold to libraries, schools and families. The format had strengths: named authors, editorial review and a stable text. It also had limits. A set was expensive to print and distribute, took years to revise, and began to age from the moment it was published. Publishers issued yearbooks and occasional new editions to keep up.
Encyclopedias on discs
In the late 1980s and 1990s, personal computers with CD-ROM drives opened a new route. A whole encyclopedia could fit on a few discs, and could include search, hyperlinks between articles, audio clips and short videos. Some titles sold to households as part of home computing bundles, and schools bought them for school computer labs. The prices were lower than for printed sets, and the products competed on features such as searchability.
These were still edited by publishers, and updates arrived as a new disc each year. The web soon offered an alternative that could change daily.
The wiki idea
The core technology behind collaborative reference work was the wiki. In the mid-1990s, the programmer Ward Cunningham created a site where any visitor could edit pages directly in the browser and could create new pages by simply linking to a title that did not yet exist. The word comes from a Hawaiian term meaning quick. The design was simple: pages, links, an edit button, and a history of changes so that mistakes could be undone.
That history of changes is the central safeguard. Because every edit is recorded, vandalism can be reverted and disagreements can be traced, so openness and accountability work together.
Volunteer-written encyclopedias
In 2000 an online encyclopedia project called Nupedia began, using a structured process in which experts wrote and reviewed articles. Progress was slow. In January 2001 a companion project based on wiki software was launched to speed up drafting, and it grew far faster than the expert-run project. It became Wikipedia, and over the following years it expanded to many languages and millions of articles. Its stated aims included neutral presentation and verifiable sources, and its content was released under open licenses that allow reuse.
Several other online encyclopedias existed or followed, including commercial ones and specialized ones, and some used editing models closer to traditional publishing. Ownership, governance and licensing vary among them.
The decline of printed sets
The effects on the print trade were substantial. Sales of large printed encyclopedias fell sharply in the late 1990s and 2000s. One of the oldest English-language sets, the Encyclopaedia Britannica, announced in 2012 that it would stop printing new editions and continue digitally. The causes were several: low-priced discs, free web content, easier search, and changing family buying habits. Which factor mattered most is debated.
How the content is made
Open-editing sites rely on communities. In broad terms:
- Anyone can propose changes, though some pages are restricted when they attract repeated disruption.
- Experienced volunteers patrol recent changes, discuss disputes on talk pages and enforce guidelines.
- Sources matter. Policies ask editors to support claims with published references rather than personal opinion.
- Automation helps. Software tools flag likely vandalism and formatting problems.
This system tends to work well on popular topics with many watchers and less well on obscure ones, where errors can remain for long periods.
Reliability and criticism
Studies and opinions on the accuracy of open encyclopedias vary, and a fair summary is that they are often useful starting points but should not be treated as final authorities. Common criticisms include:
- Uneven coverage. Topics that interest the contributing community may be covered in depth, while others are thin.
- Demographic skews. Contributor groups are not representative of the whole population, which can affect what is written and how.
- Edit disputes. Contested topics can see repeated reversions, and what appears on a page at any moment may depend on who is active.
- Lack of named experts. Readers cannot always see an author’s credentials, unlike in a signed print article.
Defenders point to openness, constant correction, citations that readers can check, and the fact that traditional encyclopedias also contained errors and editorial biases. Many teachers advise students to use such sites for background and then verify claims with the cited sources.
Beyond encyclopedias
The wiki format spread to many uses: company knowledge bases, software documentation, game guides, fan communities and personal notes. Many of these resemble earlier hypertext systems, now with simple multi-user editing. Search tools also began to use reference sites heavily, showing summaries drawn from them directly on results pages, which has raised discussion about how readers reach the original sources.
Other pressures are visible too. Online learning materials and automated answer systems now compete with reference sites for attention, and questions about how to sustain volunteer communities and funding continue.
The larger shift
The movement from shelves to discs to wikis changed who writes reference works and how fast they change. It traded some editorial control and signed authorship for scale, speed and low cost, and it made verifying sources more important for readers. Neither model is perfect, and many people use both depending on the question.