post hoc fallacy

Examples of post hoc fallacy in the following topics:

• The Regression Fallacy

  • The regression fallacy fails to account for natural fluctuations and rather ascribes cause where none exists.
  • The regression (or regressive) fallacy is an informal fallacy.
  • It is frequently a special kind of the post hoc fallacy.
  • Assuming the pain relief was caused by the doctor is fallacious.
  • Incidentally, some experiments have shown that people may develop a systematic bias for punishment and against reward because of reasoning analogous to this example of the regression fallacy.

• Correlation is Not Causation

  • This fallacy is also known as cum hoc ergo propter hoc, Latin for "with this, therefore because of this," and "false cause. " Consider the following:
  • As with any logical fallacy, identifying that the reasoning behind an argument is flawed does not imply that the resulting conclusion is false.
  • The cum hoc ergo propter hoc logical fallacy can be expressed as follows:
  • This is a logical fallacy because there are at least five possibilities:
  • While well-established, this relationship is still susceptible to logical fallacy due to the complexity of the system.

• Independence considerations in conditional probability

  • Casinos do employ this practice; they post the last several outcomes of many betting games to trick unsuspecting gamblers into believing the odds are in their favor.
  • This is called the gambler's fallacy.

• Further Discussion of ANOVA

  • Follow-up tests are often distinguished in terms of whether they are planned (a priori) or post hoc.
  • Planned tests are determined before looking at the data, and post hoc tests are performed after looking at the data.
  • Post hoc tests, such as Tukey's range test, most commonly compare every group mean with every other group mean and typically incorporate some method of controlling for type I errors.

• Elements of a Designed Study

• Kruskal-Wallis H-Test

  • Therefore, a researcher might use sample contrasts between individual sample pairs, or post hoc tests, to determine which of the sample pairs are significantly different.

• Comparing Three or More Populations: Randomized Block Design

  • If the $p$-value is significant, appropriate post-hoc multiple comparisons tests would be performed.

• Glossary

  • When the comparison among means is decided on after viewing the data, the comparison is called an "unplanned comparison" or a post-hoc comparison.