In addition to standard methods such as bootstrap analysis or cophenetic correlation, BIONUMERICS employs proprietary technology to assess the reliability of clusters for any clustering algorithm and data set. The method is based on resampling/permutation techniques operating at the data level or at the similarity level and is designed as a framework encompassing all available clustering algorithms in BIONUMERICS. The method enumerates the reliability of dendrograms or networks in function of degeneracies as well as poorly resolved clusters and can calculate consensus trees or networks that impose a minimum reliability threshold on each resolved cluster. This method sheds new light on the problem of cluster significance and the reliability of tree and network inferring algorithms and is an invaluable asset in interpreting clustering trees and networks.