Anecdotal evidence

Last updated

Anecdotal evidence is evidence based only on personal observation, collected in a casual or non-systematic manner.

Contents

When used in advertising or promotion of a product, service, or idea, anecdotal reports are often called a testimonial, which are highly regulated [1] in some jurisdictions.

When compared to other types of evidence, anecdotal evidence is generally regarded as limited in value due to a number of potential weaknesses, but may be considered within the scope of scientific method as some anecdotal evidence can be both empirical and verifiable, e.g. in the use of case studies in medicine. Other anecdotal evidence, however, does not qualify as scientific evidence, because its nature prevents it from being investigated by the scientific method. Where only one or a few anecdotes are presented, there is a larger chance that they may be unreliable due to cherry-picked or otherwise non-representative samples of typical cases. [2] [3] Similarly, psychologists have found that due to cognitive bias people are more likely to remember notable or unusual examples rather than typical examples. [4] Thus, even when accurate, anecdotal evidence is not necessarily representative of a typical experience. Accurate determination of whether an anecdote is typical requires statistical evidence. [5] Misuse of anecdotal evidence in the form of argument from anecdote is an informal fallacy [6] and is sometimes referred to as the "person who" fallacy ("I know a person who..."; "I know of a case where..." etc.) which places undue weight on experiences of close peers which may not be typical.

Scientific context

In science, definitions of anecdotal evidence include:

Anecdotal evidence can have varying degrees of formality. For instance, in medicine, published anecdotal evidence by a trained observer (a doctor) is called a case report, and is subjected to formal peer review. [11] Although such evidence is not seen as conclusive, researchers may sometimes regard it as an invitation to more rigorous scientific study of the phenomenon in question. [12] For instance, one study found that 35 of 47 anecdotal reports of drug side-effects were later sustained as "clearly correct." [13]

Anecdotal evidence is considered the least certain type of scientific information. [14] Researchers may use anecdotal evidence for suggesting new hypotheses, but never as validating evidence. [15] [16]

If an anecdote illustrates a desired conclusion rather than a logical conclusion, it is considered a faulty or hasty generalization. [17]

In any case where some factor affects the probability of an outcome, rather than uniquely determining it, selected individual cases to prove nothing; e.g. "my grandfather smoked two packs a day until he died at 90" and "my sister never smoked but died of lung cancer". Anecdotes often refer to the exception, rather than the rule: "Anecdotes are useless precisely because they may point to idiosyncratic responses." [18]

In medicine, anecdotal evidence is also subject to placebo effects. [19]

See also

Related Research Articles

The phrase "correlation does not imply causation" refers to the inability to legitimately deduce a cause-and-effect relationship between two events or variables solely on the basis of an observed association or correlation between them. The idea that "correlation implies causation" is an example of a questionable-cause logical fallacy, in which two events occurring together are taken to have established a cause-and-effect relationship. This fallacy is also known by the Latin phrase cum hoc ergo propter hoc. This differs from the fallacy known as post hoc ergo propter hoc, in which an event following another is seen as a necessary consequence of the former event, and from conflation, the errant merging of two events, ideas, databases, etc., into one.

<span class="mw-page-title-main">Fallacy</span> Argument that uses faulty reasoning

A fallacy, also known as paralogia in modern psychology, is the use of invalid or otherwise faulty reasoning in the construction of an argument that may appear to be well-reasoned if unnoticed. The term was introduced in the Western intellectual tradition by the Aristotelian De Sophisticis Elenchis.

Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms or supports one's prior beliefs or values. People display this bias when they select information that supports their views, ignoring contrary information, or when they interpret ambiguous evidence as supporting their existing attitudes. The effect is strongest for desired outcomes, for emotionally charged issues, and for deeply entrenched beliefs. Confirmation bias is insuperable for most people, but they can manage it, for example, by education and training in critical thinking skills.

Paranormal events are purported phenomena described in popular culture, folk, and other non-scientific bodies of knowledge, whose existence within these contexts is described as being beyond the scope of normal scientific understanding. Notable paranormal beliefs include those that pertain to extrasensory perception, spiritualism and the pseudosciences of ghost hunting, cryptozoology, and ufology.

The genetic fallacy is a fallacy of irrelevance in which arguments or information are dismissed or validated based solely on their source of origin rather than their content. In other words, a claim is ignored or given credibility based on its source rather than the claim itself.

A faulty generalization is an informal fallacy wherein a conclusion is drawn about all or many instances of a phenomenon on the basis of one or a few instances of that phenomenon. It is similar to a proof by example in mathematics. It is an example of jumping to conclusions. For example, one may generalize about all people or all members of a group from what one knows about just one or a few people:

Introspection is the examination of one's own conscious thoughts and feelings. In psychology, the process of introspection relies on the observation of one's mental state, while in a spiritual context it may refer to the examination of one's soul. Introspection is closely related to human self-reflection and self-discovery and is contrasted with external observation.

<span class="mw-page-title-main">Cherry picking</span> Fallacy of incomplete evidence

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 and similar cases or data that may contradict that position. Cherry picking may be committed intentionally or unintentionally.

Inductive reasoning is a method of reasoning in which a general principle is derived from a body of observations. It consists of making broad generalizations based on specific observations. Inductive reasoning is distinct from deductive reasoning, where the conclusion of a deductive argument is certain given the premises are correct; in contrast, the truth of the conclusion of an inductive argument is probable, based upon the evidence given.

An anecdote is "a story with a point", such as to communicate an abstract idea about a person, place, or thing through the concrete details of a short narrative or to characterize by delineating a specific quirk or trait. Occasionally humorous, anecdotes differ from jokes because their primary purpose is not simply to provoke laughter but to reveal a truth more general than the brief tale itself.

<span class="mw-page-title-main">Logical reasoning</span> Process of drawing correct inferences

Logical reasoning is a mental activity that aims to arrive at a conclusion in a rigorous way. It happens in the form of inferences or arguments by starting from a set of premises and reasoning to a conclusion supported by these premises. The premises and the conclusion are propositions, i.e. true or false claims about what is the case. Together, they form an argument. Logical reasoning is norm-governed in the sense that it aims to formulate correct arguments that any rational person would find convincing. The main discipline studying logical reasoning is called logic.

Optimism bias is a cognitive bias that causes someone to believe that they themselves are less likely to experience a negative event. It is also known as unrealistic optimism or comparative optimism.

In logic and mathematics, proof by example is a logical fallacy whereby the validity of a statement is illustrated through one or more examples or cases—rather than a full-fledged proof.

Evidence of absence is evidence of any kind that suggests something is missing or that it does not exist. What counts as evidence of absence has been a subject of debate between scientists and philosophers. It is often distinguished from absence of evidence.

An argument from authority, also called an appeal to authority, or argumentum ad verecundiam, is a form of argument in which the mere fact that an influential figure holds a certain position is used as evidence that the position itself is correct. While it is not a valid form of logical proof, it is a practical and sound way of obtaining knowledge that is generally likely to be correct when the authority is real, pertinent, and universally accepted.

<span class="mw-page-title-main">Woozle effect</span> False credibility due to quantity of citations

The Woozle effect, also known as evidence by citation, occurs when a source is widely cited for a claim it does not adequately support, giving said claim undeserved credibility. If results are not replicated and no one notices that a key claim was never well-supported in its original publication, faulty assumptions may affect further research.

Intuitive statistics, or folk statistics, is the cognitive phenomenon where organisms use data to make generalizations and predictions about the world. This can be a small amount of sample data or training instances, which in turn contribute to inductive inferences about either population-level properties, future data, or both. Inferences can involve revising hypotheses, or beliefs, in light of probabilistic data that inform and motivate future predictions. The informal tendency for cognitive animals to intuitively generate statistical inferences, when formalized with certain axioms of probability theory, constitutes statistics as an academic discipline.

An argument from anecdote is an informal logical fallacy, where anecdotal evidence is presented as an argument; without any other contributory evidence or reasoning. This type of argument is considered as an informal logical fallacy as it is unpersuasive – since the anecdote could be made up, misconstrued or be a statistical outlier which is insignificant when further evidence is considered. This fallacy can often be found in conjunction with the hasty generalisation fallacy – where the hasty generalisation is made from unsubstantiated anecdotes.

References

  1. ↑ "Guides Concerning the Use of Endorsements and Testimonials in Advertising" (PDF). FTC.gov.
  2. ↑ Weiten, Wayne (2010). Psychology: Themes and Variations. Wadsworth/Cengage Learning. p. 75. ISBN   9780495601975.
  3. ↑ Goodwin, C. James (2009). Research in Psychology: Methods and Design. John Wiley & Sons. p. 25. ISBN   9780470522783.
  4. ↑ Gibson, Rhonda; Zillman, Dolf (1994). "Exaggerated Versus Representative Exemplification in News Reports: Perception of Issues and Personal Consequences". Communication Research. 21 (5): 603–624. doi:10.1177/009365094021005003. S2CID   145050644.
  5. ↑ Schwarcz, Joe; Barrett, Stephen. "Some Notes on the Nature of Science". Archived from the original on 20 September 2012. Retrieved 16 June 2022.{{cite web}}: CS1 maint: unfit URL (link)
  6. ↑ "Fallacies | Internet Encyclopedia of Philosophy". www.iep.utm.edu. Retrieved 2020-04-07.
  7. ↑ "anecdotal". YourDictionary.com. Retrieved 17 June 2019.
  8. ↑ "Nechako White Sturgeon Recovery Initiative - Glossary - NWSRI". www.nechakowhitesturgeon.org. Retrieved 2020-04-07.
  9. ↑ "Anecdotal evidence - Smart Health Choices - NCBI Bookshelf". www.ncbi.nlm.nih.gov. Retrieved 2020-04-07.
  10. ↑ "No Love for Anecdotal Evidence". NeuroLogica Blog. 2007-03-08. Retrieved 2020-04-07.
  11. ↑ Jenicek, M. (1999). Clinical Case Reporting in Evidence-Based Medicine. Oxford: Butterworth–Heinemann. p. 117. ISBN   0-7506-4592-X.
  12. ↑ Vandenbroucke, J. P. (2001). "In Defense of Case Reports and Case Series". Annals of Internal Medicine. 134 (4): 330–334. doi:10.7326/0003-4819-134-4-200102200-00017. PMID   11182844. S2CID   867759.
  13. ↑ Venning, G. R. (1982). "Validity of anecdotal reports of suspected adverse drug reactions: the problem of false alarms". Br Med J (Clin Res Ed). 284 (6311): 249–52. doi:10.1136/bmj.284.6311.249. PMC   1495801 . PMID   0006799125.
  14. ↑ Riffenburgh, R. H. (1999). Statistics in Medicine. Boston: Academic Press. pp.  196. ISBN   0-12-588560-1.
  15. ↑ Lilienfeld, Scott O.; Lynn, Steven Jay; Lohr, Jeffrey M. (2014). "Initial Thoughts, Reflections, and Considerations". Science and Pseudoscience in Clinical Psychology (2 ed.). New York: Guilford Publications. p. 9. ISBN   9781462517510. Testimonial and anecdotal evidence can be quite useful in the early stages of scientific investigation. Nevertheless, such evidence is almost always much more helpful in the context of discovery (i.e., hypothesis generation) than in the context of justification (i.e., hypothesis testing [...]).
  16. ↑ Mebius, A. (2022). "Against 'instantaneous' expertise". Philosophy, Ethics, and Humanities in Medicine. 17 (11): 11. doi: 10.1186/s13010-022-00123-3 . PMC   9490894 . PMID   36127693. S2CID   252384889.
  17. ↑ Thompson B. Fallacies. Archived April 20, 2006, at the Wayback Machine
  18. ↑ Sicherer, Scott H. (1999). "Food allergy: When and how to perform oral food challenges". Pediatric Allergy and Immunology. 10 (4): 226–234. doi:10.1034/j.1399-3038.1999.00040.x. PMID   10678717. S2CID   1484234.
  19. ↑ "Evaluating Treatment Products". MedicineNet.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.