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Uncontrolled Factors |
| Description: | ||
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| The argument draws a conclusion based on a comparison between two (or more) groups, even though some important difference between the groups, other than the difference specified by the experiment, may be responsible for the results obtained. | ||
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| Comments: | ||
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| This fallacy applies only to inductive arguments that draw a conclusion from a special kind of sample, called a "controlled" sample, in which the sample is divided into distinct groups for purposes of comparison. The simplest such division is into two groups known as an "experimental" group and a "control" group. | ||
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| Examples: | ||
| "We compared a group of college-educated men to a group of women who had not gone to college. Our study showed that men are significantly smarter than women." | ||
| "We studied two groups of heart patients. One group received prayers from a local charismatic church. The other group did not. The group that was prayed for, which was treated primarily by Dr. Albert, received less pain medication than the other group, which was treated primarily by Dr. Baker. We conclude that prayer helps control pain." [However, Dr. A is generally more conservative in his use of pain medication than Dr. B.] | ||
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| Discussion: | ||
| "Controlling" for various factors means making sure that those factors do not affect the results of the experiment. For example, some experiments have to be conducted at various times of the day and night to make sure that time of day does not affect the results. Some experiments have to be conducted at many different locations to make sure that location does not affect the results. It is impossible to control for every factor that might turn out to be relevant. That is why Inductive Arguments cannot guarantee a true conclusion. However, a carefully conducted experiment controls for every factor that is suspected of being relevant. | ||
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| Classification: An Error in Sampling (an inductive fallacy of soundness with a falsehood in the minor premiss). | ||
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| Source: The term "uncontrolled factors" is widely used by researchers, and any good research methods text book should contain a discussion of the topic. I doubt that an original source for the term can be identified, although the term was probably not used before the 20th century with the development of modern research methods in psychology. I believe mine is the first list to explicitly include the fallacy of Uncontrolled Factors as one of the common errors in inductive reasoning. | ||
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