In: Statistics and Probability
What are the p-value correction methods for ANOVA tests and why they are important? Please explain.
The Bonferroni test, also known as the "Bonferroni correction" or "Bonferroni adjustment" suggests that the "p" value for each test must be equal to alpha divided by the number of tests.
Importance -
A Bonferroni test is a type of multiple comparison test used in statistical analysis.
During hypothesis testing with multiple comparisons, errors or false positives can occur.
Bonferroni designed a test or an adjustment to prevent data from incorrectly appearing to be statistically significant.
For example,
An error rate of 5% might typically be assigned to a test, meaning that 5% of the time, there'll be a false positive. The 5% error rate is called the alpha level. However, when many comparisons are being made in a test, the error rate for each comparison can impact the results, creating multiple false positives.
Bonferroni designed a method of correcting for the increased error rates in hypothesis testing that had multiple comparisons. Bonferroni's adjustment is calculated by taking the number of tests and dividing it into the alpha value. Using the 5% error rate from our example, two tests would yield an error rate of 0.025 or (.05/2) while four tests would have an error rate of .0125 or (.05/4) .