Anecdotal evidence
Anecdotal evidence ( anecdotal evidence, anecdotal evidence, case report ) is an informal report on evidence in the form of a single report or hearsay. The term is often used as a contrast to the empirical evidence ( eg clinical studies, laboratory studies, field studies) and the analogy and has a weak argumentative significance.
Anecdotal evidence is usually not developed by scientific means evidence, since it closes itself by their very nature of scientific methodology ( methodology) and, for example, is not reproducible.
Definition
The term anecdotal evidence involved a detailed description of a specific example or case which often reflect the opinion or experience of the describer. These case descriptions are neither statistically nor in any other way scientifically verifiable, often unreliable and are therefore considered epistemically problematic. In some ways, the anecdotal evidence due to their weak expressiveness serves as a contrast to the statistical evidence.
Areas of application
Misuse of anecdotal evidence is a logical fallacy and is sometimes informally " someone " fallacy referred to as ( " I know someone who ..." " I know of a case where " ), comparable to the hasty generalization. Anecdotal evidence is not necessarily typical. Statistical evidence can more accurately determine how typical something is.
In all forms of anecdotal evidence, there may be doubt as to whether their reliability can be tested by objective, independent investigation. This is a consequence of the informal way in which this information is collected, documented and / or presented. The term is often used for evidence, for which there is no documentation. Thus, the verification depends on the credibility of the party presenting the evidence.
Science
The endeavor of the anecdotal evidence is to be distinguished from the statistical evidence, which consists deriving general trends and patterns. In the statistical evidence, the number of respondents on the reliability of the information and evidence determined. However, the most important element of the statistical analysis are the questions themselves, the precise design of the questions is to guarantee that the answers of the respondents were not predetermined or subjectively influenced. In contrast, the anecdotal evidence is not concerned with or hardly verifiable trends and patterns, but rather with a detailed presentation of specific cases or examples nearby. Researchers who actually use the anecdotal evidence, often tend then to authorize results when a large number of small examples or cases suggest a trend. According to a scientific understanding individual case may not be well represented and not initiate scientific evolution.
Everyday life
Anecdotal statements can be very convincing and are referred to as the " someone " fallacy in everyday life. Examples of anecdotal statements are often with "I know someone who ..." or " I know of a case where " initiated. A psychological study found that students have relied more on the statements of isolated students in choosing their courses, as a statistic, which was reflected as a representative majority has rated the course. The reason for this was stated that a story is much more tangible and therefore easier memorizing.
Anecdotal evidence is not always incorrect or untrue, but often builds only on a false inference. An example is: "My grandfather smoked like a chimney, but died completely healthy in a car accident at the age of 99 years. " This statement can the fact that smoking is the likelihood of various diseases increases markedly, neither refute nor can the contrary evidence. In this case, the evidence may be given, although in reality, yet they are no guarantee for the conclusion. The generalization of this one case to other similar cases is impossible, since the given circumstances and the behavior of the protagonists may differ. Thus, anecdotal evidence, so high their veracity may be, not be used as a valuable scientific evidence.
Advertising
In advertising, the principle of anecdotal evidence is increasingly being used to generate based on the experiences and stories of others, trust in the product from the audience. Particularly credible is the representation of the product of so-called experts. So the Advertise a dentist applies a specific toothpaste brand as particularly credible.
Medicine
In medicine anecdotal evidence is of great importance. Cases of miraculous healing to refute clinical or economic studies and refer to a contradictory conclusion. Anecdotal statements about similar symptoms and their effect on patient outcome often more interesting and vivid than mere statistics. The scientists were able to Ubel, Jepson and Baron confirmed using a series of experiments. Her research question was: " What is crucial for the treatment decision of patients? " You experimental setup provided that the participants will be provided on the one hand fictitious statistical information on the percentage of cardiac patients whose health has improved by vasodilation or bypass surgery. On the other hand, they received letters of recommendation from hypothetical patients who have either benefited by any of those interventions or non profits.
The proportion of patients receiving one or the other used the treatment and did not help was varied within the scope of the experiment, so that he behaved either proportional or proportional to the statistical information. The result of the scientist points to a significant influence of patient referrals attention to the types of treatment chosen by the participants.
Importance for communication and argumentation theory
An important role is played by the distinction between statistical and anecdotal evidence in the communication and argumentation theory. Hoeken and Hustinx deal in one of their studies with the quality of arguments. In corresponding experiments, they find that the persuasiveness of both types of evidence is critically dependent on the type of argument used. Based on a generalization of an argument, as statistical evidence is usually more persuasive. Based on the argument but an analogy, as statistical and anecdotal evidence are equally compelling for the participants of the experiment.
Furthermore, it is represented in part in science that the respective cultural background is relevant as to which types of evidence are considered more convincing.