Contents
What does Bonferroni correction do?
Purpose: The Bonferroni correction adjusts probability (p) values because of the increased risk of a type I error when making multiple statistical tests. Some studies quoted adjusted p values incorrectly or gave an erroneous rationale.
What can I use instead of Bonferroni correction?
Instead of using the Bonferroni correction, you can use the Holm correction. It is strictly more powerful than Bonferroni, and is valid under the same assumptions. It also controls the FWER. Suppose you have m p-values.
What is wrong with Bonferroni adjustments?
The first problem is that Bonferroni adjustments are concerned with the wrong hypothesis. If one or more of the 20 P values is less than 0.00256, the universal null hypothesis is rejected. We can say that the two groups are not equal for all 20 variables, but we cannot say which, or even how many, variables differ.
Why is Bonferroni correction bad?
What occurs with a type 1 error?
A type I error occurs during hypothesis testing when a null hypothesis is rejected, even though it is accurate and should not be rejected. A type I error is “false positive” leading to an incorrect rejection of the null hypothesis.
Which is an example of the Bonferroni correction?
For example, if we perform three statistical tests at once and wish to use α = .05 for each test, the Bonferroni Correction tell us that we should use αnew = .01667. Thus, we should only reject the null hypothesis of each individual test if the p-value of the test is less than .01667.
Which is more powerful the Bonferroni correction or the Sidak correction?
There are alternative ways to control the familywise error rate. For example, the Holm–Bonferroni method and the Šidák correction are universally more powerful procedures than the Bonferroni correction, meaning that they are always at least as powerful.
Which is better technique 2 or technique 3?
Since the p-value for Technique 2 vs. Technique 3 is the only p-value less than .01667, she concludes that there is only a statistically significant difference between technique 2 and technique 3.