Articles for traditional encyclopedias such as Encyclopædia Britannica are written by experts, lending such encyclopedias a reputation for accuracy.[164] However, a peer review in 2005 of forty-two scientific entries on both Wikipedia and Encyclopædia Britannica by the science journal Nature found few differences in accuracy, and concluded that "the average science entry in Wikipedia contained around four inaccuracies; Britannica, about three."[165] Joseph Reagle suggested that while the study reflects "a topical strength of Wikipedia contributors" in science articles, "Wikipedia may not have fared so well using a random sampling of articles or on humanities subjects."[166] Others raised similar critiques.[167] The findings by Nature were disputed by Encyclopædia Britannica,[168][169] and in response, Nature gave a rebuttal of the points raised by Britannica.[170] In addition to the point-for-point disagreement between these two parties, others have examined the sample size and selection method used in the Nature effort, and suggested a "flawed study design" (in Nature's manual selection of articles, in part or in whole, for comparison), absence of statistical analysis (e.g., of reported confidence intervals), and a lack of study "statistical power" (i.e., owing to small sample size, 42 or 4 × 101 articles compared, vs >105 and >106 set sizes for Britannica and the English Wikipedia, respectively).[171]
