Evidence based on personal experience that hasn't been scientifically tested. Usually means observations and reports that are passed on by word of mouth.

Everyday observations of behaviour that appear to be consistent with a psychological explanation. Anecdotal evidence (of a theory) is not really evidence at all and cannot be used by itself to support a theory.

observations of treatment effects in nonscientific studies, without controls, not blind. These observations cannot prove anything in themselves but sometimes provide leads for useful research.

Evidence made up of one or more anecdotes. In science, an anecdote is a story about a person's experience, told by that person.

Anecdotal evidence is an informal account of evidence in the form of an anecdote or hearsay. The term is often used in contrast to scientific evidence, especially evidence-based medicine, which are types of formal accounts. Anecdotal evidence is often unscientific because it cannot be investigated using the scientific method.