Experts:
I need some assistance with performing an ANOVA given a) unequal sample sizes and b) unequal proportions. Allow me to summarize the problem based on some sample/illustrative data:
Let’s say I have 3 groups (and # of reported incidents in that group):
- Group Alpha reported 150 incidents
- Group Bravo reported 30 incidents
- Group Charlie reported 50 incidents
So, while the Alpha group reported 3 times as many incidents than the Charlie group, the Alpha group is 12 times larger than the Charlie group. So, shouldn't the # of incidents be a function of # of people within the group?
In other words, proportionally speaking, the proportions are: 5%, 7.5%, and 20%, respectively . That is, ...
- Alpha has 3,000 people… so only 5.00% (150/3,000) out of the Alpha group report(ed) incidents
- Bravo has 400 people… so, 7.50% (30/400) out of the Bravo group report(ed) incidents
- Charlie has 250 people… so, 20.00% (50/250) out of the Charlie group report(ed) incidents
Given the proportions (e.g., Charlie group had 50 incidents *less* than the Alpha group), the Charlie group is essentially the “worst offender” given they only have a fraction of people in that group.
All that said, how would you take the proportions into consideration when performing the ANOVA? What are the steps in JMP prior (or after) executing the ANOVA?
Thank you,
EEH
