Type II error is a statistical error that occurs when a null hypothesis that is actually false is not rejected. This means that the test incorrectly concludes that there is no effect or relationship when there actually is one. It is also known as a false negative.
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Google Gemini AI
Apr 29
Type II Error
In statistical hypothesis testing, a Type II error occurs when:
- The null hypothesis (H0) is true (meaning there is no significant difference or effect). - The test fails to reject H0 (i.e., it concludes that there is no significant difference or effect).
Consequences:
A Type II error means that:
- The research failed to detect a true difference or effect that exists in the population. - The conclusion of the study is false negative. - The investigator may miss out on important findings that could have practical implications.
How to Reduce Type II Error:
- Increase sample size: A larger sample size increases the power of the test, making it more likely to detect a true difference if it exists. - Use a more sensitive statistical test: Some statistical tests are more sensitive than others, meaning they are more likely to detect a difference if it exists. - Use a one-tailed test instead of a two-tailed test: If you have a specific direction of the expected difference, a one-tailed test can increase the power of the test. - Specify an appropriate alpha level: A smaller alpha level (e.g., 0.01 instead of 0.05) makes the test more conservative, reducing the risk of a Type II error. - Consider the effect size: The effect size measures the magnitude of the difference or effect being tested. A larger effect size makes it easier to detect a significant difference.
Relationship to Type I Error:
Type II error is related to Type I error (false positive):
- A high risk of Type II error (i.e., low power) means there is also a low risk of Type I error. - A low risk of Type II error (i.e., high power) means there is also a higher risk of Type I error.