There are a list of references in the help for SVM, and one refers to probabilities: Wu, T.-F., C.-J. Lin, and R. C. Weng. (2004). “Probability estimates for multi-class classification by pairwise coupling.” Journal of Machine Learning Research, 5:975-1005, URL http://www.csie.ntu.edu.t...svmprob/svmprob.pdf.