Title: Anecdotal evidence - Wikipedia
Headings: Anecdotal evidence
Anecdotal evidence
Contents
Scientific context
Law
Scientific evidence as legal evidence
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References

Content: "the report of an experience by one or more persons that is not objectively documented or an experience or outcome that occurred outside of a controlled environment"
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. 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. For instance, one study found that 35 of 47 anecdotal reports of drug side-effects were later sustained as "clearly correct." Anecdotal evidence is considered the least certain type of scientific information. Researchers may use anecdotal evidence for suggesting new hypotheses, but never as validating evidence. Anecdotal evidence is often unscientific or pseudoscientific because various forms of cognitive bias may affect the collection or presentation of evidence. For instance, someone who claims to have had an encounter with a supernatural being or alien may present a very vivid story, but this is not falsifiable. This phenomenon can also happen to large groups of people through subjective validation . Anecdotal evidence is also frequently misinterpreted via the availability heuristic, which leads to an overestimation of prevalence.