Should I use Bonferroni or Tukey?
For those wanting to control the Type I error rate he suggests Bonferroni or Tukey and says (p. 374): Bonferroni has more power when the number of comparisons is small, whereas Tukey is more powerful when testing large numbers of means.
Why do we need Bonferroni correction?
Purpose: The Bonferroni correction adjusts probability (p) values because of the increased risk of a type I error when making multiple statistical tests.
Why is Scheffe test conservative?
This test is quite conservative because this test is valid for all possible contrasts of the means. Therefore the Scheffé procedure is equivalent to the F-test, and if the F-test rejects, there will be some contrast that will not contain zero in its confidence interval.
What does a Scheffe test tell us?
The Scheffe Test (also called Scheffe’s procedure or Scheffe’s method) is a post-hoc test used in Analysis of Variance. The Scheffe test corrects alpha for simple and complex mean comparisons. Complex mean comparisons involve comparing more than one pair of means simultaneously.
What is Bonferroni test used for?
The Bonferroni test is a statistical test used to reduce the instance of a false positive. In particular, Bonferroni designed an adjustment to prevent data from incorrectly appearing to be statistically significant.
Which is better Scheffe or Bonferroni post hoc test?
While the Scheffe post-hoc test is the most flexible, it is also the most conservative and produces the widest confidence intervals. This means it has the lowest statistical power and the lowest ability to detect true differences between the groups. Note that the Scheffe post-hoc test can be used whether or not the group sample sizes are equal.
How to conduct an ANOVA with the Scheffe test?
ANOVA with Scheffe Post Hoc Test in SPSS – YouTube This video demonstrates how to conduct an ANOVA with a Scheffe post hoc test in SPSS. The Scheffe test is often used when group sizes are unequal. This video demonstrates how to conduct an ANOVA with a Scheffe post hoc test in SPSS. The Scheffe test is often used when group sizes are unequal.
How does Bonferroni adjust error rate for multiple comparisons?
No adjustment is made to the error rate for multiple comparisons. · Bonferroni. Uses t tests to perform pairwise comparisons between group means, but controls overall error rate by setting the error rate for each test to the experimentwise error rate divided by the total number of tests.
When to use Scheffe Test vs Tukey’s HSD?
Compared to Tukey’s HSD, Scheffe has less Power when making pairwise (simple) comparisons, but more Power when making complex comparisons. It is appropriate to use Scheffe test only when making many post hoc complex comparisons (e.g. more than k-1).