Citing Wikipedia in Court Opinions

Fire Insurance Exchange v. Oltmanns (Utah Ct. App. Aug. 16, 2012) discusses the practice, and the concurrence goes into even more detail. From the majority opinion:

In the past, we might have hesitated to cite Wikipedia in a judicial opinion given its reputation — perhaps not well deserved — for unreliability.  See, e.g., Wikipedia Survives Research Test, BBC News (Dec. 15, 2005), (finding rate of error in scientific articles to be about the same as between Wikipedia and Encyclopedia Britannica).  But the increasing trend of using Wikipedia in judicial opinions over the last decade seems to demonstrate a growing recognition of its value in some contexts, as noted in one 2010 article that found that by that year Wikipedia had been cited in over four hundred judicial opinions.  See Lee F. Peoples, The Citation of Wikipedia in Judicial Opinions, 12 Yale J. L. & Tech. 1, 1 (2009–2010) (reviewing several instances in which Wikipedia has been cited in judicial opinions and critiquing its usefulness, or lack thereof, in those contexts). Judge Posner argued in 2007 that “Wikipedia is a terrific resource … [p]artly because it [is] so convenient, it often has been updated recently and [it] is very accurate,” after citing it in United States v. Radomski, 473 F.3d 728, 731 (7th Cir. 2007).  See Noam Cohen, Courts Turn to Wikipedia, but Selectively, N.Y. Times, Jan. 29, 2007 at C3. While a prudent person would avoid a surgeon who bases his or her understanding of complicated medical procedures on an online source whose contributors range from expert scholars to internet trolls, where an understanding of the vernacular or colloquial is key to the resolution of a case, Judge Posner is correct that Wikipedia is tough to beat. A fuller explanation of the propriety of citing Wikipedia is set forth in Judge Voros’s separate opinion.

And here’s Judge Voros’s concurrence:

I concur fully in the lead opinion. I write separately to explain why I believe that opinion appropriately cites Wikipedia in construing the term “jet ski” in the insurance contract at issue here. Wikipedia has been cited in hundreds of American judicial opinions, including one issued by the Utah Supreme Court. See State v. Alverez, 2006 UT 61, ¶ 16 n.5, 147 P.3d 425 (citing a Wikipedia entry on Jesus Malverde). But today’s lead opinion is the first time this court has cited it.

Wikipedia is a “free, collaboratively edited, and multilingual Internet encyclopedia” whose 22 million articles (over 4 million in English) are written by volunteers. Wikipedia, Wikipedia, (as of Aug. 13, 2012, 18:48 GMT). Most of its articles can be edited by anyone with access to the site. Wikipedia claims to be “the largest and most popular general reference work on the Internet,” with “an estimated 365 million readers worldwide” and “2.7 billion monthly pageviews from the United States alone.” Id. (footnotes omitted).

Because Wikipedia is an open‐source project, questions arise as to its reliability. Indeed, Wikipedia’s own article on the subject references various studies as well as opposing views from librarians, academics, experts in science and medicine, and editors of other encyclopedias. See Wikipedia, Reliability of Wikipedia, wiki/Reliability_of_Wikipedia (as of Aug. 13, 2012, 18:51 GMT). In addition, most or all Wikipedia entries include a broad disclaimer on the entry’s citation page:

IMPORTANT NOTE: Most educators and professionals do not consider it appropriate to use tertiary sources such as encyclopedias as a sole source for any information — citing an encyclopedia as an important reference in footnotes or bibliographies may result in censure or a failing grade. Wikipedia articles should be used for background information, as a reference for correct terminology and search terms, and as a starting point for further research. As with any community‐built reference, there is a possibility for error in Wikipedia’s content — please check your facts against multiple sources and read our disclaimers for more information.

Wikipedia, Cite Page: Jet Ski, Special:Cite&page=Jet_Ski&id=493156065 (as of Aug. 13, 2012, 18:52 GMT). [Footnote: Reliability may also be an issue for the Wikipedia citation itself:

A defining feature of Wikipedia is that its entries are in a constant state of change. The impermanent nature of the information on Wikipedia has serious consequences when Wikipedia entries are cited in judicial opinions. Unless they are provided with a date‐ and time‐specific citation, researchers who pull up a Wikipedia entry cited in a judicial opinion will never be absolutely certain they are viewing the entry as it existed when the judge viewed it…. This may ultimately lead to uncertainty and instability in the law.

Lee F. Peoples, The Citation of Wikipedia in Judicial Opinions, 12 Yale J.L. & Tech. 1, 38–39 (2009–2010). Fortunately, each Wikipedia entry has a “Cite this page” link showing citations to that entry in various styles, including the style prescribed by the Harvard Journal of Law & Technology. That journal’s citation style, which I have followed in this opinion, is more specific than ordinary Bluebook citation style.]

Citing Wikipedia is as controversial as it is common. [Footnote: “Many citations by judges, often in footnotes, are … beside the main judicial point, [and] appear intended to show how hip and contemporary the judge is ….” Noam Cohen, Courts Turn to Wikipedia, but Selectively, N.Y. Times, Jan. 29, 2007, available at The lead opinion’s citation to Wikipedia is obviously not of this type.] Some courts approve it, others condemn it. Compare United States v. Lawson, 677 F.3d 629, 650 (4th Cir. 2012) (stating that the court is “troubled by Wikipedia’s lack of reliability”), Bing Shun Li v. Holder, 400 Fed. App’x 854, 857–58 (5th Cir. 2010) (expressing “disapproval of the [immigration judge]’s reliance on Wikipedia and [warning] against any improper reliance on it or similarly unreliable internet sources in the future”), Badasa v. Mukasey, 540 F.3d 909, 910–11 (8th Cir. 2008) (noting Wikipedia’s acknowledgment that, “at any given moment,” an entry “could be in the middle of a large edit or it could have been recently vandalized” (citation and internal quotation marks omitted)), and In re Marriage of Lamoure, 132 Cal. Rptr. 3d 1, 15 (Cal. Ct. App. 2011) (“We do not consider Wikipedia a sufficiently reliable source” for defining the term “noncustodial.”), with Prude v. Clarke, 675 F.3d 732, 734 (7th Cir. 2012) (citing Wikipedia entry, in the context of an Eighth Amendment challenge, for the proposition that an anal fissure “is no fun at all”), United States v. Brown, 669 F.3d 10, 18 & n.12 (1st Cir. 2012) (citing Wikipedia for its definition of “sovereign citizen movement,” one of a criminal defendant’s “atypical legal beliefs”), Murdock v. Astrue, 458 Fed. App’x 702, 705 n.3 (10th Cir. 2012) (citing Wikipedia for “some examples of block lengths from cities in this country”), and State v. Ballard, 2012‐ NMCA‐043, ¶ 19 n.1, 276 P.3d 976 (N.M. Ct. App. 2012) (citing Wikipedia to define “peer‐to‐peer file sharing”).

A recent law review article by Professor Lee F. Peoples examines in depth the issues surrounding the citation of Wikipedia in judicial opinions. See Lee F. Peoples, The Citation of Wikipedia in Judicial Opinions, 12 Yale J.L. & Tech. 1 (2009–2010). While Wikipedia is gaining acceptance among judicial writers, Professor Peoples notes that reliance on Wikipedia has occasionally been held to be erroneous: [A]ppellate courts have reversed or found error in lower court decisions [for] relying on Wikipedia entries for psychological research in a child custody case, for attempting to refute expert medical testimony with a Wikipedia entry, and perhaps most egregiously for denying an asylum seeker’s request based on information obtained from Wikipedia. Id. at 45 (footnotes omitted) (citing Badasa, 540 F.3d at 909; Campbell v. Secretary of Health & Human Servs., 69 Fed. Cl. 775, 781 (2006); D.M. v. Department of Children & Family Servs., 979 So. 2d 1007, 1010 (Fla. Dist. Ct. App. 2008), reh’g en banc granted (May 14, 2008)).

Professor Peoples extracts from the case law “several bright line rules for when a Wikipedia entry should not be cited in a judicial opinion.” Id. at 28. For example, he suggests that “[c]ourts should not take judicial notice of Wikipedia content,” because that content “is disputable and its accuracy can be reasonably questioned.” Id. He also states that “Wikipedia should not be cited when a more authoritative source exists for the information.” Id. at 29. In particular, Wikipedia is a poor source “to define technical or scientific terms.” Id. at 46. And he cautions that “[a] Wikipedia entry should not be relied upon as the only basis for a court’s holding, reasoning, or logic,” given the encyclopedia’s “numerous shortcomings” discussed in his article. Id. at 29.

[Footnote: Among its shortcomings — and strengths — is Wikipedia’s fluidity. Anyone can edit a Wikipedia entry at any time, making it vulnerable to “‘opportunistic editing.’” See Noam Cohen, Courts Turn to Wikipedia, but Selectively, N.Y. Times, Jan. 29, 2007, available at (quoting Professor Cass Sunstein). Thus, “‘an unscrupulous lawyer (or client) could edit the Web site entry to frame the facts in a light favorable to the client’s cause.’” Peoples, 12 Yale J.L. & Tech. at 24 (quoting R. Jason Richards, Courting Wikipedia, Trial, Apr. 2008, at 63). Opportunistic editing is detectable, however. Every article on Wikipedia has a “View history” tab with links to all previous edits, the dates of each edit, and the user name or IP address of each editor. The revision history also allows the reader to view an article in each of its previous iterations. By this method, we can see that the three possible meanings of the term “jet ski” discussed in the lead opinion were part of the Wikipedia article before the present dispute arose. See Wikipedia, Jet Ski, (as of June 3, 2005, 06:32 GMT). Further, as Professor Peoples notes, “[a] database called WikiScanner allows a researcher to dig deeper into the revision of a Wikipedia article.” Id. at 25 (citing WikiScanner, (last visited by Peoples Dec. 16, 2009)).]

However, Professor Peoples acknowledges “some limited instances where it is appropriate for a Wikipedia citation to appear in a judicial opinion.” Id. at 30. Some are obvious, such as where the Wikipedia entry itself is at issue or where the court must address a Wikipedia entry cited by a party. See id. In addition, the evolving nature of Wikipedia “makes it a good source for definitions of new slang terms, for popular culture references, and for jargon and lingo including computer and technology terms.” Id. at 31 (citing “tweaking,” “phreakers,” and “screenshot”).

Relevant here, Professor Peoples also states that “Wikipedia entries can be useful in some limited situations … for getting a sense of a term’s common usage.” Id. at 50. In particular, he recognizes the utility of Wikipedia in the interpretation of terms appearing in insurance contracts: The collaborative process used to create Wikipedia entries makes them potentially useful to courts in specific situations. In several cases courts attempting to interpret insurance contracts have turned to Wikipedia entries for evidence of the common usage or ordinary and plain meaning of a contract term. This method of interpretation [i.e., looking to common usage] “has long been recognized, and has been applied in the context of various types of insurance.” Wikipedia has been used in this context to define the terms “recreational vehicle” and “car accident.” Id. at 32 (footnotes omitted) (quoting 2 Couch on Insurance § 22:38 (2005), and citing Laasmar v. Phelps Dodge Corp. Life, Accidental Death & Dismemberment & Dependent Life Ins. Plan, No. 06‐cv‐00013‐MSK‐MJW, 2007 WL 1613255, at *4 n.5 (D. Colo. June 1, 2007); Fergison v. Stonebridge Life Ins. Co., No. 271488, 2007 WL 286793, at *3 (Mich. Ct. App. Feb. 1, 2007) (per curiam)). See also Colony Nat’l Ins. Co. v. Hing Wah Chinese Rest., 546 F.20100462‐CA 12 Supp. 2d 202, 209 n.9 (E.D. Pa. 2008) (citing Wikipedia in a discussion of the meaning of the term “restaurant” in an insurance policy).

Of course, getting a sense of the common usage or ordinary and plain meaning of a contract term is precisely the purpose for which the lead opinion here cites Wikipedia. Our reliance on this source is therefore, in my judgment, appropriate. Moreover, here Wikipedia does not stand alone. As appellants note, the Macmillan online dictionary defines “Jet Ski” as “a very small fast boat for one or two people that you drive standing up.” Macmillan Dictionary, american/Jet‐Ski (last visited Aug. 13, 2012).

Finally, we need not nail down the one true meaning of “jet ski” in this case. Whatever meaning the drafters of the insurance policy may have intended, our task is to determine whether they employed “language which clearly and unmistakably communicates … the specific circumstances under which the expected coverage will not be provided,” Alf v. State Farm Fire & Cas. Co., 850 P.2d 1272, 1275 (Utah 1993), or whether, on the contrary, there is “a range of possible meanings” that the term may bear in this context, see In re E.Z., 2011 UT 38, ¶ 103, 266 P.3d 702 (Lee, J., concurring in part and concurring in the judgment). Whatever its shortcomings in other contexts, for this task, an open‐source encyclopedia with many editors and millions of readers seems just the ticket.