if you are using SPSS and are familiar with it I would suggest the following for such a small set of samples. First, from your email you imply you have two sample sets ergo to symetric matrices. I recommend the folowing which all can be done in SPSS: 1) reduce the two matrices using principal components. Make sure have the same number of eigenvectors produced. 2) rotate the resulting PCA of one set onto the other using a Promax rotation. You have map each matrix into the same coordinate space. 3) after the rotation and/or the PCA you can see the RSquare the fit of one matrix on the other. SPSS with small samples as your works dandy! N Gottlieb ProfileDepot, Inc. you wrote: Hi All, I am a doctoral candidate studying in the UK. As part of my research, I use card sorting tasks to investigate underlying cognitive structures of prospective teachers within a subject domain. The result of this card sorting task is a symmetrical matrix with 56 rows and 56 columns. What I want to do is to correlate two matrices which represents an expert's categorisation of the cars and a subject's categorisation. Here I have the problem. I do not know how to do this. Can you help me in solving my problem? I am reasonably familiar with SPSS. Is it possible to do this with SPSS? Or do I need another program? Thank you very much for your interest and time. Ufuk YILDIRIM