In essence, you have panel data.
I cannot see that Mann-Whitney is
appropriate for any comparison
unless you throw away all the
information on changes over time.
Nick
[email protected]
[email protected]
> Sorry, but I'm confused! I ran two treatments and 32
> subjects (organised
> in group of 4) participated to each treatment (10 periods). This means
> that I have only 8 independent observations in each period for each
> treatment. How should be my dataset to run the mann-whitney test? If I
> consider 320 observations in each treatment, I cannot say
> that they are
> independent. How should I perform the test in this case?
> > There is some misunderstanding here, I guess.
> >
> > Mann-Whitney requires at a minimum all
> > the individual ranks. It can't work on just
> > input of averages, or even medians.
> >> I have to run the mann-whitney test to check the difference
> >> in the trend
> >> between two treatments in a public good game experiment.
> >> This test has to be run on average contributions of groups.
> >> Does it mean
> >> that I should have in my dataset a single observation for
> >> each group that
> >> represents the average contribution of the group over all
> the periods?
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