Thanks to Jay Wang and Ivan Zezula's ranking formulae (see "Rank Awful" postings) I have produced an Excel spreadsheet to calculate both correlation coefficients for Pogo's data. > 1. I have two sets of scores which are related to each other. > SET A 1100,1040,950,1090,1050,970,900,1110,940,880 > SET B 108,128,113,103,112,119,96,103,112,92. > My question is do I use Pearson's or Spearman's. Depends on your question! If you are expecting for a linear relationship between A and B then use Pearson's r, if you are looking for a monotonic relationship then use Spearman's rho. If you just want to describe the relationship between the variables then produce a scatterplot; it looks like there is a non-monotonic relationship (see the scatterplot in the spreadsheet). In which case neither correlation coefficient would be appropriate. Dr Graham D. Smith Psychology Division School of Behavioural Studies University College Northampton Boughton Green Road Northampton NN2 7AL Tel (01604) 735500 Ext 2393 Email [EMAIL PROTECTED]
