The sale of traditional encyclopaedias moved away from door-to-door sales to the ‘added value’ that came along with CD or DVD versions in the mid-90s. These disc-based versions sold well for a while and even encouraged some new players, like Microsoft and Dorling Kindersley, to get in on the act.

Then the internet, with its free information philosophy, killed a lot of that market off. And when somebody said the magic word ‘Wiki’, the whole encyclopaedia compilation process was re-invented.

Rather than relying on panels of scholars to disseminate their knowledge from the top down, now anybody with some niche knowledge can create and edit topics, from the bottom up. But how good is Wikipedia’s free, community-written encyclopaedia model? Does it now make its paid-for DVD rivals a waste of money?

Wikipedia and vandalised pages

Wikipedia has received a lot of flack in the last year or so for articles which have been vandalised, sometimes quite subtly, to give misleading, if not plain wrong, information.

"Some articles are vandalised a lot," writes Nicholson Baker in the Guardian. "On January 11 this year, the entire fascinating entry on the aardvark was replaced with 'one ugly animal'; in February the aardvark was briefly described as a 'medium-sized inflatable banana'".

Admittedly, this has only happened to a small percentage of pages and mainly to those detailing autobiographies of living people, but it has tarnished Wikipedia's reputation. If you bear in mind the kind of pages that are most likely to be corrupted, they will be ones where the ‘editors’ can gain personal or commercial advantage.

Few people will want to alter the Wikipedia details of the Trojan wars, the demise of the dodo or the history of Wall Street. Be aware that erroneous edits do occur, and check anything that seems outlandish with a second source. But the vast majority of Wikipedia is filled with valuable and accurate information.

There’s little doubt Wikipedia is a lot more extensive than any DVD-based resource too. The space available to writers is far larger than for the articles in Britannica or World Book and many Wikipedia texts go into more detail.

Most major articles have good external references and lots of photos or illustrations. Some have links to the Wikimedia Commons project, which offers many more supporting items. There are 60 pictures of Dartmoor, for example.

There are inevitably holes in the Wikipedia knowledge set, where authors haven’t been found for specific subjects. Unlike the other encyclopaedias, articles aren’t commissioned (though requests for entries are put in article ‘stubs’, to show where topics need coverage).

Is there still a future for encyclopaedias?

The two DVD-based encyclopaedias, Britannica and World Book, have more moving media like videos and simulations, and put things together so there are different ways to get at their content.

There’s no equivalent to Britannica’s Brainstormer in Wikipedia, for instance, a browser which links together different subjects so you start to get an idea of the way the web of human knowledge works.

World Book also aims itself at secondary school students, so its language reflects that. For instance, it starts its article on color (aka colour) with the line "Color fills our world with beauty". It shows its origins with these US spellings and American accents in the commentaries.

One of the oddest things about electronic encyclopaedias and their physical counterparts is the price difference. While the DVD-based products reviewed here are around £30, the printed and bound version of World Book Encyclopaedia 2008 is £785, while the 32 volumes of Encyclopaedia Britannica cost £995.

Since the electronic versions contain the same text as the printed ones and include extras like audio and video content which aren’t available in the print editions, you have to really value well-bound books to pay the extra.