Novel means and methods for analyzing hybridization data derived from hybridization assays between a target nucleic acid and differently sequenced polynucleotide probes involve selecting probe sets that define reference sequences for sequence signatures and deriving useful data about the nature of the target nucleic acid molecule based on its hybridization to the probes. The methods are useful for determining whether the target contains a nucleic acid or polypeptide sequence signature, whether the target encodes a member of a gene family, or whether the target is derived from one of any number of genes.