Abstract: The present invention relates generally to a method for assessing data sets, such as multi-parametric data sets. More particularly, the present invention contemplates a method for determining differences between objects in a data set wherein each object is described using one or more parameters. The present invention is particularly useful inter alia in the field of bioinformatics such as to determine differences in populations of nucleotide or amino acid sequences [100]. Such differences are referred to herein as polymorphisms such as polymorphisms within a sequence database. Populations so identified [110] may provide a fingerprint of inter alia a particular nucleic acid molecule, protein, trait or disease condition. The present invention extends, however, to identifying sub-populations of data relevant inter alia to commerce, industry or the environment.