- Thread starter AniBioUSA
- Start date

Is a Tukey possible when the data sets are independent?

...You may also want to think about adjusting the p values for multiple comparisons.

I'm a little confused by your response. I think it is a bit complicated for what I'm doing.

I already did all the ANOVA stuff.

I have responses to a survey from 6 continents. My number of subjects for each continent ranges from 5-290.

They responded to 8 pictures using a scale of 1-10.

I needed to compare the means from each continent for each picture. I already ran the ANOVA for each picture and go significant results for 6 of the 8 pictures.

I then did a Tukey's HSD and got significant results again for a few of the pairs.

None of the significant pairs included the continent with the lowest number responders (5). Is that because there weren't enough responders?

The fact that there is significant results does that mean that these are the continents that differ the most in opinion?

Hi Ani,

As I wrote, to assume normality sample size of each continent should be more than 30. (say 5 is not so good ...)

you need to assume normality for each continent.

I also suggested you run the Brown–Forsythe test for equality of variances.

correct. Standard deviation (average)= S/Sqrt(n)

This says the "actual significance level" is bigger than the "significance level" you used for each question. you can understand if you calculate the following simple question:

The probability of a mistake in one question is p=0.05. what is the probability for mistake asking 8 questions?

PS test for equality of variances. : http://www.statskingdom.com/230var_levenes.html

Cheers

As I wrote, to assume normality sample size of each continent should be more than 30. (say 5 is not so good ...)

you need to assume normality for each continent.

I also suggested you run the Brown–Forsythe test for equality of variances.

None of the significant pairs included the continent with the lowest number responders (5). Is that because there weren't enough responders?

"...You may also want to think about adjusting the p values for multiple comparisons."

The probability of a mistake in one question is p=0.05. what is the probability for mistake asking 8 questions?

PS test for equality of variances. : http://www.statskingdom.com/230var_levenes.html

Cheers

Last edited: