I'll start by saying that I'm a neuroscience PhD student and have searched a long time for a solution to this problem but I can't find one. If you just have time to give a rough idea or point in the right direction then I'm grateful for any help.
I am measuring the frequency of the same material under four different conditions, i.e.
Condition 1 = 1 2 3 1 2 1 2 3 1 3
Condition 2 = 1 3 2 1 1 1 2 2 1 1 2 1
Condition 3 = 1 2 1 2 1 2 1 2 2
Condition 4 = 10 12 11 9 8 11 14 12 11
I have lots of these data sets, the number of measurements in each condition varies and they are not necessarily equal, however the group sizes don't deviate much from 10.
It is obvious that in condition 4 the frequency was consistently higher, however, I can't find a good statistical test to show this. I can run an Anova to see if there is an underlying significant distribution (just now I'm using a permutation F test) but this doesn't tell me specifics. I can run multiple comparisons but then the p-value is driven down because I have to compare every group to every other group before I can say the frequency was higher in condition 4 than in any of the others.
Basically, I am writing a piece of code in Matlab to analyse data sets as shown above, but I need a test which I can run on the data and which will tell me if the groups are all similar, if one is significantly higher than the rest, if two are higher than the other two etc etc. The condition with the highest frequency is not always the same one and often there are conditions which have statistically similar frequencies.
I have looked for ever to find a good test or method but I just can't find one, they all require equal group sizes or independent groups or normally distributed data.
Any help would be greatly appreciated,
Roddy.
I am measuring the frequency of the same material under four different conditions, i.e.
Condition 1 = 1 2 3 1 2 1 2 3 1 3
Condition 2 = 1 3 2 1 1 1 2 2 1 1 2 1
Condition 3 = 1 2 1 2 1 2 1 2 2
Condition 4 = 10 12 11 9 8 11 14 12 11
I have lots of these data sets, the number of measurements in each condition varies and they are not necessarily equal, however the group sizes don't deviate much from 10.
It is obvious that in condition 4 the frequency was consistently higher, however, I can't find a good statistical test to show this. I can run an Anova to see if there is an underlying significant distribution (just now I'm using a permutation F test) but this doesn't tell me specifics. I can run multiple comparisons but then the p-value is driven down because I have to compare every group to every other group before I can say the frequency was higher in condition 4 than in any of the others.
Basically, I am writing a piece of code in Matlab to analyse data sets as shown above, but I need a test which I can run on the data and which will tell me if the groups are all similar, if one is significantly higher than the rest, if two are higher than the other two etc etc. The condition with the highest frequency is not always the same one and often there are conditions which have statistically similar frequencies.
I have looked for ever to find a good test or method but I just can't find one, they all require equal group sizes or independent groups or normally distributed data.
Any help would be greatly appreciated,
Roddy.