I'm primarily a programmer and have little to no training in formal maths or statistics of any kind.
I'm working on my dissertation (which foolishly is about clustering data), the process is unsupervised so the cluster labels are scattered and some are differently sized to the ground truth.
I've looked about and read about confusion matrices, the rand index and purity etc and I assume what I'm looking for is an external validation method but which one is a little bit beyond me.
I'm looking to calculate the accuracy of the cluster outputs, but some are differently sized to the ground truth and since its unsupervised the cluster labels won't match. What method of validation should I be using?