Is there a statistical program to calculate power for data generated by assigning a score (not necessarily linear ie score of 2 may not be equal to twice a score of 1)
I assume that your score is ordinal but not interval in that ratios cannot be equated. Then you can apply rank tests to the data to compare results for two different groups. The statistical test that is appropriate for comparing unpaired data is the Wilcoxon rank sum test. If you specify a difference in medians that you would like to be able to detect and the sample size that you have, there are programs available to determine the power of the test. nQuery Advisor is one computer package that will do this. In SAS the power procedure can do this.