Visual stability analysis for model selection in graded possibilistic clustering

When compared to standard clustering, fuzzy clustering provides more flexible and powerful data representation. Most fuzzy methods require setting some parameters, as is the case for the Graded Possibilistic c-Means clustering method, which has two parameters in addition to number of centroids. However, for this model selection task there is no well established criterion available. Building on our own previous work on fuzzy clustering similarity indexes, we introduce a technique to evaluate the stability of clusterings by using the fuzzy Jaccard index, and use this procedure to select the most suitable values of parameters. The experiments indicate that the procedure is effective for fuzzy and possibilistic clustering.