a method of improving the speed with which a sample such as a biometric sample can be fuzzily matched against records in a database , comprises extracting characteristics from the sample , and using those extracted characteristics as indexes to address a lookup table . each row within the lookup table points to an individual record occurrence list which contain details of not only the stored records from which the given characteristic can be extracted , but also those records having an extracted characteristic which are within a defined proximity to the said characteristic . characteristics are extracted from the sample record , and a given stored record is identified as being a possible match with the sample if it appears in a required number of record occurrence lists .