Digital encyclopaedias put the world at your fingertips

update Digital encyclopedias Microsoft Encarta 2007, Encyclopedia Britannica 2007, and Wikipedia let you look up any subject in a second.

Door-to-door encyclopedia salespeople are a dying breed, and a wealth of the world's information is free on the Web. But that doesn't make encyclopedias obsolete. On the contrary, a trusted source is needed more than ever to help you find facts and filter a dizzying array of data in our age of information overload.

Instead of lifting leaden encyclopedic volumes and thumbing through their dusty leaves, these three digital reference tools let you locate hundreds of thousands of articles with a mere click.

We reviewed the hard drive versions of Microsoft Encarta 2007 and Encyclopedia Britannica 2007 as well as the online, open-source Wikipedia. In the final analysis, we found this trio of tools generally useful but not excellent.

For instance, Britannica's data appeared to be the most thorough -- thanks to more than two centuries of fine-tuning, and the experience overall was much better than in the 2006 edition, but very young learners might be turned off by so much text. By contrast, Encarta 2007 allows young children to feast their eyes on videos and images, but older scholars might be frustrated at having to click paragraph headings to read the full text of an article. And while the free Wikipedia loads in a snap in any Web browser and serves a slew of off-the-beaten-path articles, we wouldn't swear on its facts in a court of law. Wikipedia's greatest strength -- its self-regulated community that invites anyone to add and edit articles -- is also an Achilles' heel.

Which tool should you choose? Maybe more than one. For example, you could use Wikipedia for free research when you're away from your hard drive, then back up the facts by looking them up on your installed version of Britannica or Encarta. Mac users will find this an easy choice, as Encarta is Windows only.

	Encarta 2007	Britannica 2007	Wikipedia
CNET rating	7.3	7.0	6.3
Price	AU$100	AU$130	Free
Download	950MB	4.3GB via DVD, or 3.7GB on CD	None
System requirements	Windows XP SP2; online component	Mac OS X and up; Windows 2000 and up	Get online with any Web browser, even a dial-up connection will do
Number of articles	68,000	100,000+, including Britannica Book of the Year, Student and Elementary volumes	1,300,000+ in English; hundreds of thousands more in 62 other languages
Integrity of data	Updated weekly; originally based on Funk & Wagnalls Encyclopedia	Updated quarterly; Britannica's bound volumes have been published since the 18th century	Updated daily; any user can post and edit entries -- even you
For kids	Encarta Kids (ages 7 to 12); provides parental content controls; Homework Help now folded into the $99 Microsoft Student	Britannica Student Library (ages 10 to 14); Britannica Elementary Library (ages 6 to 10); Homework help; games	Wikijunior.org under construction
Translation dictionary	Yes; Student 2007 offers more	Yes; and Languages of the World includes record-yourself pronunciation guides	Yes, Wiktionary
Interactive atlas	Yes	Yes	No
Multimedia	300 animated sequences and Discovery Channel videos; 2,500 sound and music clips	Thousands of videos, sound clips, and images	290,000+ media files in the Wikimedia Commons
Timelines	Yes	Yes	Yes
Unique features	The Visual Browser clusters topics; rich Timelines	BrainStormer clusters topics; GeoAnalyzer compares country data; Timelines	Wikispecies directory; Wikiquote lookups; Wikinews; Wikibooks; Wikisource
Privacy	Register with Microsoft Passport/Windows Live account; asks to monitor your usage, which you can decline	Personal registration questions optional, but required for tech support	Your visits are undetected, unless you log in to add and edit content