Two-way anova with unequal sample sizes

1. Can you do a two-way ANOVA with unequal sample sizes?
2. How do you compare two unequal sample sizes?
3. Why is unequal n usually a bad thing in an ANOVA?
4. Can you do an ANOVA with unequal variance?

Can you do a two-way ANOVA with unequal sample sizes?

Yes it will work very well. ANOVA works with the mean and thus, does not bother whether samples are equal or not.

How do you compare two unequal sample sizes?

One way to compare the two different size data sets is to divide the large set into an N number of equal size sets. The comparison can be based on absolute sum of of difference. THis will measure how many sets from the Nset are in close match with the single 4 sample set.

Why is unequal n usually a bad thing in an ANOVA?

The problem with unequal n is that it causes confounding. The difference between weighted and unweighted means is a difference critical for understanding how to deal with the confounding resulting from unequal n. Weighted and unweighted means will be explained using the data shown in Table 4.

Can you do an ANOVA with unequal variance?

Unfortunately, simulation studies find that this assumption is a strict requirement. If your groups have unequal variances, your results can be incorrect if you use the classic test. On the other hand, Welch's ANOVA isn't sensitive to unequal variances.