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Cherry picking

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Cherry picking, suppressing evidence, or the fallacy of incomplete evidence is the act of pointing to individual cases or data that seem to confirm a particular position, while ignoring a significant portion of related cases or data that may contradict that position. It is a kind of fallacy of selective attention, the most common example of which is the confirmation bias. Cherry picking may be committed unintentionally.[1]

The term is based on the perceived process of harvesting fruit, such as cherries. The picker would be expected to only select the ripest and healthiest fruits. An observer who only sees the selected fruit may thus wrongly conclude that most, or even all, of the fruit is in such good condition.

Cherry picking can be found in many logical fallacies. For example, the "fallacy of anecdotal evidence" tends to overlook large amounts of data in favor of that known personally, "selective use of evidence" rejects material unfavorable to an argument, while a false dichotomy picks only two options when more are available.

Acceptability

When a person is assigned to advocate a particular position, then cherry picking might be seen as entirely appropriate. For example, defense lawyers are free to present any evidence supporting the innocence of their client. By contrast, while prosecutors are expected to present the strongest case consistent with the facts, they are not permitted to suppress evidence that might support the innocence of the defendant.

Additionally, in common law, guilt has to be proven beyond reasonable doubt and thus the introduction of 'cherry picked' evidence by the defence is regarded as entirely appropriate, because, while such data may not prove something in general, it may be successful in introducing the needed minimum level of doubt to successfully defend the case.

However, when a person with a supposedly neutral position cherry picks, for example journalists, scientists, and judges, that is generally regarded as inappropriate.

In business

Cherry picking is also used to refer to business policies of picking out profitable customers from a large base.[citation needed] An example of this use is that by insuring only healthy people and refusing to insure those who were unhealthy or are likely to become unhealthy, a health insurance company can cherry pick the most profitable customers.

If an automobile insurance company insured only good drivers by cherry picking them from among all drivers this would enable a company to gain an advantage over a company that insures all drivers. To prevent automobile insurance companies from cherry picking only the good drivers and leaving poorer drivers without any insurance, most states in the U.S.A. use an assigned risk scheme to require automobile insurance companies to insure a certain number of drivers with poor records.

Retail

In a retail environment, especially one in which employees earn commission, an employee may observe two customers on the sales floor: one browsing through high-end, expensive merchandise, and another looking at smaller, low-cost items. Assuming that the resulting transaction would reflect a boost in personal sales performance and yield more commission, the employee decides to offer assistance to the first customer and ignores the second customer, instead of taking the opportunity to upsell each of them. Such a tactic is generally regarded as poor salesmanship, and coworkers might label the employee as a cherry picker.

Cherry-picking employees may also be prone to profiling customers, making assumptions about their buying habits based on their age, ethnicity, spoken accent, grooming, hygiene, or how they dress.

In statistics

Cherry picking can refer to the selection of data or data sets so a study or survey will give desired, predictable results which may be misleading or even completely contrary to actuality.[2]

In science

“Choosing to make selective choices among competing evidence, so as to emphasize those results that support a given position, while ignoring or dismissing any findings that do not support it, is a practice known as “cherry picking” and is a hallmark of poor science or pseudo-science.” – Richard Somerville, Testimony before the U.S House of Representatives Committee on Energy and Commerce Subcommittee on Energy and Power, March 8, 2011 [1]

"Good science looks at all the evidence (rather than cherry picking only favorable evidence), controls for variables so we can identify what is actually working, uses blinded observations so as to minimize the effects of bias, and uses internally consistent logic." [2]

In revision control

In the jargon of revision control, cherry picking is used to describe the action of selecting which patches (or changesets, or commits) should be ported from one branch to another.[3][4][5]

In sports

Cherry picking in sports is the tactic of waiting close to the opponent's goal in hope of receiving the object in play (ball, puck etc.) and redirecting it towards the goal. The tactic can degrade the quality of game play, so to prevent or discourage the practice, several team sports have an off-side rule. Ice hockey, for example, requires that a player not enter the offensive zone before the puck. (See Loafing.)

In Australian taxation

In the 1970s and early 1980s in Australia, cherry picking was a tax avoidance scheme based on tax deductions for company contributions to a superannuation fund. Such a fund was notionally for the benefit of employees, but the benefits (the "cherries") were picked by the company or its owners.

See also

References

  1. ^ The Internet Encyclopedia of Philosophy, "Fallacies", Bradley Dowden (2010)
  2. ^ Ben Goldacre. Bad Science. Fourth Estate. pp. 97–9. ISBN 978-0-00-728487-0.
  3. ^ Meier, J. D. (November 21, 2007). Team Development with Microsoft Visual Studio Team Foundation Server: Patterns and Practices. Microsoft Press. p. 216. ISBN 978-0-7356-2571-6. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  4. ^ Wingerd, Laura (November 18, 2005). Practical Perforce. O'Reilly Media, Inc. p. 317. ISBN 978-0-596-10185-5.
  5. ^ Loeliger, Jon (May 15, 2009). "Using git cherry-pick". Version Control with Git. O'Reilly Media, Inc. ISBN 978-0-596-52012-0.