I have done a piece of research with 4 other people where we looked at 80 images and scored them using 2 methods. we scored each image twice using each method. I am now a bit stuck on which are the best statistics to use to analyse the scores. I've done the correlation coefficient and worked out the varience. is there a way of working out he standard deviation and what is the best way of going about it? I have Excel if that makes things easier. help!!