Comparing Groups 2 Flashcards
What are non-parametric tests?
Statistical methods used when data do not meet the assumptions necessary for parametric tests, such as normality.
When is the Wilcoxon Signed Rank Test used?
To compare two related samples and assess whether their population mean ranks differ.
What is the null hypothesis (H0) for the Wilcoxon Signed Rank Test?
The median of the differences between paired observations is zero.
What type of data is appropriate for the Wilcoxon Signed Rank Test?
Skewed continuous data and ordinal data.
What is the Mann-Whitney U Test used for?
To compare two independent groups to determine whether they come from the same distribution.
What is the null hypothesis (H0) for the Mann-Whitney U Test?
The distributions of both groups are equal.
What type of data is suitable for the Mann-Whitney U Test?
Skewed continuous data and ordinal data.
What is the first step in applying the Wilcoxon Signed Rank Test?
Calculate differences and ranks between paired observations.
What is the significance level typically used to reject the null hypothesis?
0.05.
What is an example research question for the Wilcoxon Signed Rank Test?
Is there a significant difference in test scores before and after a training program?
What is Fisher’s Exact Test used for?
To compare proportions between two independent groups, particularly useful for small sample sizes.
What are the assumptions for Pearson’s Chi-Square Test?
- Observations are randomly and independently drawn
- The number of cells with expected frequencies less than 5 is < 20%
- Minimum expected frequency is at least 1
- Observations are not paired.
Fill in the blank: The _______ is a non-parametric test used when comparing a single sample median to a known value in the presence of non-normality.
1 Sample Wilcoxon Signed-Rank Test
What is the purpose of the McNemar Test?
To evaluate changes in paired observations, such as pre-test and post-test results.
What do you do if the data type is categorical and you want to compare it across two independent groups?
Use Pearson’s χ2 Test or Fisher’s Exact Test for small expected counts.
