# Cluster analysis comparison

I have a question about cluster analysis and I hope you can help me. I tested a sample of 30 patients with same scales (A, B, C, D, E, F) and I obtained two clusters, one with the results of two scales (A and B) and another with the results of other four different scales (C, D, E, F). I want to compare this two clusters that have a great similarity to find the overlapping of the clusters obtained in one and in the other one and validate the result. What kind of analysis should I do?

• I don't understand. Did you (1) obtained two clusters of the 30 patients (some in one group, some in the other) using information from 6 variables (A–F) or (2) there are two cluster analyses, one using two variables (A,B) and the other based on patient values on four variables (C–F)? Do you want to compare (1) the two groups for their values on the 6 variables or (2) the results of different cluster analyses? Feb 13, 2013 at 19:02
• I explain better. I had tested 30 patients with three scales, the last one is made of four variables. Than I did a cluster analysis of the 30 patients with the first two scales (A e B, two variables) and I obtain the first dendrogram. After this I did a cluster analysis of the 30 patients with the third scale that contain four variables (C,D,E,F) using the same method and distance of the first analysis and I obtain the second dendrogram.
– M_N
Feb 13, 2013 at 19:13
• Now I want to calculate the overlapping of this two dendrogram, that have many cluster in common, for example, the first cluster of the first dendrogram contain the patients 1,2,3 and the second cluster of the second dendrogram contain the patient 1,2,3,4. I would like to calculate this overlapping and show that this is not casual.
– M_N
Feb 13, 2013 at 19:14
• Maybe something like a cross-clasification? Do the clusters have some attached meaning/interpretation (high, low, ill, normal)? If you want to compare the scales themselves, have you thought in comparing them directly (without forming groups first) like in a canonical correlation or a correlation among PCA first axes? Feb 13, 2013 at 19:35
• Look for the "multiclus" workshops, and browse through these publications. They may point you to relevant methods. Feb 13, 2013 at 19:41