Within-Groups ANOVA. Chapter 13. One-Way Within-Groups ANOVA. Similar to paired-samples t -tests Same participants do something multiple (more than 2) times Are used when we have one IV with at least 3 levels, a scale DV, and the same participants in each group.
Similar to paired-samples t-tests
Same participants do something multiple (more than 2) times
Are used when we have one IV with at least 3 levels, a scale DV, and the same participants in each group
We reduce error due to differences between the groups.
We know that the groups are identical for all of the relevant variables because each group includes exactly the same participants.
We are able to reduce within-groups variability due to differences for the people in our study across groups.
Step 1. Identify populations, distribution, and assumptions.
Step 2. State the null and the research hypotheses.
Step 3. Determine characteristics of the comparison distribution.
Step 4. Determine critical values.
Step 5. Calculate the test statistic.
Step 6. Make a decision.
R2 can be calculated for this type of ANOVA, too!
You need to calculate the standard error before using the Tukey HSD testTukey HSD
We can analyze our data as if the same people are in each group, giving us additional statistical power.Matched Groups