Comparing samples with different sizes

#1
Hello!
I have 6 groups of different observers that performed the same task but have different sizes:
A - 196
B - 195
C - 80
D - 35
E - 32
F - 48
Assuming that the variables are independent and data assume a non-para metric distribution, how can I compare these groups? Which is the best statistical test to do it?
Thank you very much!!
 

Karabiner

TS Contributor
#2
There is no nonparamtric distribution. There are only nonparametric tests (tests which do not assume
a certain distribution of whatever). How exactely was task perfomance measured?

With kind regards

Karabiner
 
#3
I sincerely apologize for the error. Thank you.

The observer's task was to select a color from a physical stimuli presented in a monitor. The selected color was automatically converted into two chromatic coordinates: a* and b*. And it is with these coordinates that we want to analyze. Did that helped?

Thank you!
Regards,
Andreia Gomes
 

Karabiner

TS Contributor
#4
I do not know what a chromatic co-ordinate is. Is it a continuous measurement (at least interval scaled)?
And do you want to compare a* and b* jointly between groups, or each co-ordinate separately?

With kind regards
 
#5
a* or b* is a quantitative and continuous variable. Similar to the cartesian coordinates (x and y) in a two-dimensional space: it can take on negative or positive values. As they represent different colors, they should be evaluated separately. Do you need more information?