Abstract: Embodiments of the present invention provide a method and system for comparative analysis of data records. In particular embodiments of the present invention enable a computer system to provide a template lattice as an input to computer implemented abstraction of data from records for comparative analysis, abstract record data, map one or more record data elements to a mapped position, determine a plurality of lattice elements and a set of lattice element identifiers associated with the plurality of lattice elements to provide a characterising set for the mapped position and compare first and second data records in order to determine the degree of similarity between a first characterising set and a second characterising set for the respective first and second records. The method and system can be utilised to allow comparative analysis of recorded data that may be sensitive for the individual subjects while preserving privacy of the individual subjects.