In one aspect, an apparatus according to the invention comprises a lattice data set with a partial order of concepts (LDSWPOC) including a plurality of data elements, each of which belongs to exactly one associated concept. The set of concepts carries the structure of a partial order. Each data elements associated with a concept may be linked to one or more other data elements associated with one or more other concepts. The links define (i) a path between data elements directly linked thereby and/or (ii) a portion of a path between data elements linked by intermediate subsets of data elements. The paths define a relationship between the data elements in accord with the partial order of the concepts with which they are associated, such that selected conditions and/or constraints (collectively, “conditions”) are satisfied.