Britannica responds to Nature
Three months after the prestigious science journal Nature published a comparison of the accuracy of 42 science articles in the online version of Encyclopædia Britannica and Wikipedia (see archived story), Encyclopædia Britannica Inc (EBI) has published a response to the study. The 20-page open letter, titled "Fatally Flawed", was published in PDF format and linked from the "EB News" box at http://www.britannica.com/ on March 22. (An HTML version is also available.)
According to the Associated Press, an email from Patricia A. Ginnis (Senior Vice President at EBI) was sent to 5000 customers pointing towards the PDF file. The Wall Street Journal [1] said that EBI will also publish half-page-advertisements[2] defending their position on Monday 27 March in a group of English newspapers.
Encyclopædia Britannica Inc. denounced the Nature study, stating that "almost everything about the journal’s investigation, from the criteria for identifying inaccuracies to the discrepancy between the article text and its headline, was wrong and misleading," and called for the journal to make a public retraction of the article. EBI criticized Nature for rearranging, reediting, and excerpting Britannica articles; mistakenly identifying inaccuracies; reviewing texts that were not part of the encyclopedia proper; failing to fact-check the inaccuracies its reviewers cited; and misrepresenting its findings in the article headline and in the editorial which accompanied the news article.
EBI then went on to detail their disputes with about half of the errors found by Nature, in many cases simply rejecting the criticism outright. They indirectly acknowledged that the other half of the errors were correctly identified, and Tom Panelas, EBI spokesman, was quoted as stating that some of the errors were already known but so far had not been corrected. Neither Nature nor EBI identified how long these errors had been known at Britannica.
The Associated Press story about the dispute was widely covered in the mass media (see further press coverage).
Nature's response
On March 23, the staff of Nature published a similar PDF document, responding to EBI's accusations of "misrepresentation, sloppiness and indifference to scholarly standards". Nature firmly rejected those accusations, and stood by their belief that the comparisons were fairly made; they do not plan to make any retractions.
Nature says that EBI objected privately to the article when it was first published, but that after they (and Wikipedia) were given access to the reviewer's comments a few weeks after publication, the journal "did not receive any further correspondence until the publication of its open letter", and says it regrets the public and acrimonious nature of this exchange.
One of EBI's most vigorous objections is that the reviewers were given short excerpts of longer Britannica articles, or versions taken from their Student Encyclopedia or from past editions of their Book of the Year (which, by design, includes more personal opinion and theory than the standard EB article). Nature countered that on each website, researchers compiled whatever material was presented to them upon searching for the scientific term in question, and that the student and yearbook editions appear prominently in Britannica's search results.
EBI is correct that the study undertaken by Nature was not one of their usual, rigorously peer-reviewed scientific articles; it was a more informal survey made by journalists on their news staff, and published in their news section, separate from the articles at the heart of the journal. However, Nature says that while some editorial judgement was involved in turning reviewers' comments into numerical scores, that judgement was applied "diligently and fairly" to both encyclopedias, and that "because the reviewers were blind to the source of the material they were evaluating, and material from both sources was treated the same way, there is absolutely no reason to think that any errors they made would have systematically altered the results of our inquiry."
Wikipedia's response
Neither founder Jimmy Wales nor the collective staff of Wikipedia have made a public response to EBI's accusations. They have, however, gathered some reference information for Wikimedia Foundation volunteer press representatives to use in answering media questions. That document notes a project to correct all Wikipedia errors noted in the Nature study, created on December 22, the day Nature released the data. Thirty-four days later, on January 25, all errors were reported corrected (see archived story).
The document also says, in part, "Wikipedia, and all Wikimedia Foundation projects, are not in competition with EBI or other companies in the business of reference works. Our goals differ significantly from other reference publishers, and only overlap in that we are all striving to create accurate and useful knowledge tools."
1913 advertisement for the Britannica
''Encyclopædia Britannica'' has strongly criticised the scientific journal ''Nature'' for last year's investigation into the encyclopedia's accuracy compared to that of the open-source online encyclopedia, Wikipedia. ''Britannica'' also called for a retraction of the article. ''Nature'' has rejected the accusations, saying that their comparison was fair and that they do not intend to retract their report.

In a 20-page response (titled "Fatally Flawed") to the report's findings that there was not a significant difference in accuracy between the two encyclopædias, Britannica wrote that 'Almost everything about the journal's investigation ... was wrong and misleading.' The document goes on to call the investigation 'invalid', 'completely without merit' and 'careless'. Britannica also accused ''Nature'' of 'misrepresenting its own results'. The last 12 pages of this comprehensive rebuttal are responses to specific article criticisms, mainly consisting of differences of opinion on style and article composition, but some citing outright factual errors on ''Nature'''s part.

In their response, ''Nature'' refused to reveal their original data for comparison, and commented that ''Britannica'' had raised their grievances in private some time ago, and then received no further correspondence until ''Britannica'''s open letter of 22 March 2006. ''Nature'' notes that ''Britannica'' criticised 'less than half the points their reviewers raised', and states that the two encyclopædias were subject to the same treatment.

Wikipedia has been stigmatised as unreliable due to its open-source nature and a perceived problem with vandalism.  The December 2005 study was seen at the time as a major boost to the credibility of Wikipedia.  Jimmy Wales was notified by one of his team members, on 27 January 2006 that all corrections provided by ''Nature'' were in place.  Recent changes to some of the Wikipedia editing policies have attempted to resolve some of the reliability issues raised.

Wikipedia has yet to comment.