|This guidance essay contains comments and advice of one or more Wikipedia contributors. It is not a Wikipedia policy or guideline, though it may be consulted for assistance. A potential measure of how the community views this essay may be gained by consulting the history and talk pages, and checking What links here.|
|This page in a nutshell: Do not cherrypick. When selecting information from a source, include contradictory and significant qualifying information from the same source.|
In the context of editing an article, cherrypicking, in a negative sense, means selecting information without including contradictory or significant qualifying information from the same source and consequently misrepresenting what the source says. This applies to both quotations and paraphrasings.
Do not cherrypick.
Main information 
The main information from a source, insofar as stated in Wikipedia, must be accompanied by any contradictory and qualifying information from the same source.
Failure to do so often violates Wikipedia's neutral point of view policy, by selectively presenting one point of view from a source that actually includes both. It may also misrepresent a fringe view as mainstream or vice versa, cause undue weight, or misrepresent an unreliable source as reliable.
As to contradictory information, if, for example, a source says "Charlie loves all blue coats and hates all red coats", to report in Wikipedia that according to the same source "Charlie loves all ... coats" is cherrypicking. It is cherrypicking even if the source is precisely cited.
Timing matters. A statement at a given point in time may contradict any statement that was made earlier in time. However, a statement that is earlier in time does not contradict a later statement, even by the same person. Anyone is permitted to change their views. Generally, it does not discredit a person that they reject older views, or probably most research scientists would have no credibility. One scholar reputedly said when challenged about changing his mind, "When the facts change, I change my mind. What do you do, sir?"
Politics is a field in which changing one's mind is commonly criticized, at least in the United States. A claim is that a lack of consistency over time may make a candidate less trustworthy. However, while that may be more relevant to electing one or another candidate, it is less relevant to editing an article. We may report that a candidate held one view at one time and another view at another time, sourcing each view, or only report one view if that is all that is entitled to weight in the article, but generally the view that came later in time is not contradicted by the view that came earlier in time for purposes of reporting in Wikipedia.
Earlier and later within a single source is generally not earlier or later in time. Exceptions may occur if a single source presents chronologically ordered material, such as an anthology of dated writings, a history, or a biography. However, even if an author is known to complete the writing of one chapter before beginning research for the next, do not assume that earlier or later in a source equates with earlier or later in time unless the source's content makes that chronological ordering clear. Even in sources that appear to rely on chronology, be careful about literary devices such as flashbacks in biographies, as where a military veteran has a flashback to a wartime experience, as they can make chronologies uncertain.
Some subjects are grounded in critique of society or of another subject. For instance, a belief system may contradict another. Given that a Wikipedia article is about only one subject, not every contradiction from outside of that subject need be reported, but substantial contradiction probably should be reported or summarized as criticism.
Mixed fields of study 
Different fields of study have points of disagreement with each other. Even if the same author writes on multiple fields or disciplines in a single source, a Wikipedia article within one field of scholarship generally does not have to report contradictions emanating solely from other fields, unless they are criticisms.
- A theologian and a mathematician may contradict each other on the role of a deity in arithmetic.
- Linguists tend not to rank cultures as developed or undeveloped while sociologists tend to do exactly that, not because one is ignorantly insensitive and the other is cruelly chauvinist but because linguists need to learn the languages and ranking does not provide much help to that end while sociologists specifically study relationships between peoples and thus study rankings without necessarily agreeing with those rankings in their own value systems.
- A scientist may be expected to start with a hypothesis and challenge it with a scientific investigation to ensure thoroughness while a lawyer or detective may be expected to start with no hypothesis and find what a forensic investigation yields free of bias.
Qualifying information is information that might not contradict the main information but that alters how the main information should be understood. For example, to quote a source that says that most Americans sleep late and skip work but to ignore that the source limits that by saying "on weekends" is to omit qualifying information and misrepresent: the source on Americans' work customs. While qualifying information is infinite and cannot all be quoted or paraphrased, if it is significant, include it.
This example of qualifying information is from a book: "I have taken artistic license in conveying both reality and essence" and "[s]ome conversations ... are not intended ... as verbatim quotes."
Where to find them 
Either contradictory or qualifying information may be found anywhere in a source, not necessarily adjacent to the main information. For example, while the main information may be in a middle chapter of a book, contradictory or qualifying information may be in an endnote, in an introduction, or on a cover. Many sources are well organized and make finding everything you need relatively simple, but not all sources are so helpful.
Merely additional information 
On the other hand, merely additional information does not have to be provided. For example, if a source says "brain surgery is difficult" and goes to state the experience of a surgeon who performed it without changing the meaning of the main information, the surgeon's experience does not have to be provided in Wikipedia.
Multiple sources 
It's not cherrypicking in general to miss contradictory or qualifying information from a different source than the source that had the main information, because we don't expect editors to be familiar with all of the possible sources that could be cited on a topic. Therefore, to have gotten the main information from one source without acknowledging that it was contradicted or qualified in another source is not a valid criticism of an editor's work in Wikipedia as cherrypicking.
However, feel free to edit an article consistently with the different source, if the source is otherwise eligible to be used in Wikipedia.
It is legitimate to ask on a page's talk page once about whether cherrypicking occurred in a specific case. If your question is based on speculation, that is where you may speculate, and even then only if reasonable. Beyond that, however, it is against assuming good faith to persist in claiming that cherrypicking occurred unless evidence of it has been uncovered. You may know a subject very well and believe an article to be erroneous, but either you know it from other sourcing (but a conflict between multiple sources is not evidence of cherrypicking) or, if you know it from the same sourcing that you believe was cherrypicked by another editor, you should be able to find evidence of cherrypicking. Speculation is not an acceptable ground for continuing to challenge content as cherrypicked. In general, the better course is to find any contradictory or significant qualifying information yourself and to edit the page to reflect what you have found.
Deletion or debate 
Contradiction may justify deleting contradicted information more weakly sourced, but often it justifies presenting both sides of a topic, as by leaving intact the original statement and adding a new statement, so readers can know multiple perspectives. Which course to follow depends on the case, but hypothetical examples may illuminate the difference:
- An author says something is true and a year later retracts the statement. Usually, only report the later statement or nothing at all. The exception would be if the earlier statement remains especially notorious after the retraction and must be discussed even though it was retracted, but that is rare.
- A book says that according to one religion only persons A, B, and C are prophets but according to another religion only persons D, E, and F are prophets. Although that is contradictory, in an article about both religions both statements should be reported, perhaps in the form of a fully disclosed disagreement.
- A book's title appears to be a statement of fact but the author, inside the book or elsewhere, denies what the title says is correct as a statement of fact. This did happen with one book, the title of which placed one class of people as superior to another class, whereas inside the book the author denied that superiority. This can happen because a publisher wants a catchier title in order to encourage more sales, and some publishing contracts take control of the titles away from the authors. We do not ordinarily report a fact on the basis of a book title alone, but in a case like this we would be especially unlikely to do so.
Qualification probably does not require deletion or even debate, as long as significant qualifications are reported.
Positive meaning of cherrypicking 
A positive sense of cherrypicking is 'selecting relevant information and not selecting irrelevant information'. We're supposed to do that when writing for Wikipedia. For example, if you're writing an article about one person and basing it on a source about that person's family, you generally should select only information about the one person and ignore most information about most other people, even though they're all extensively detailed in the same source.
See also 
Notes and references 
- Although often attributed to John Maynard Keynes, that is doubted for want of a primary source (Zweig, Jason, Keynes: He Didn’t Say Half of What He Said. Or Did He?, in The Wall Street Journal (probably online only), February 11, 2011, 9:19 a.m., as accessed November 27,2012), although one blog poster argued that it is reasonable (id., June 25, 2011, 3:14 a.m.) and, given that Google said it turned up 441,000 matches for the quotation (id., article), I argue now that doubtless someone besides Keynes said it and, given the content and if said by enough people, doubtless a scholar said it and it's useful and harmless to include it here (in a non-article) with the qualification, rather than write it in my own words and less wittily, somewhat as if I invented the notion. If an attribution to a presumably now-anonymous scholar can be provided, it'll be good to add it.
- Violet, Ultra, Famous For 15 Minutes: My Years With Andy Warhol (N.Y.: Avon Books, 1st Avon Books Trade Printing April 1990, © 1988 (ISBN 0-380-70843-4)), p. v (Disclaimer).