20. The non-transitory computer readable medium of claim 19 wherein said computer program instructions further comprise computer program instructions defining the step of calculating the normalized length of the database set according to the formula: len ⁡ ( s ) = ∑ s i ∈ s ⁢ idf ⁡ ( s i ) 2 wherein: s represents the database set; len(s) represents the normalized length of the database set; and, s i represents a specific token in s.
20. The non-transitory computer readable medium of claim 19 wherein said computer program instructions further comprise computer program instructions defining the step of calculating the normalized length of the database set according to the formula: len ⁡ ( s ) = ∑ s i ∈ s ⁢ idf ⁡ ( s i ) 2 wherein: s represents the database set; len(s) represents the normalized length of the database set; and, s i represents a specific token in s. 21. The non-transitory computer readable medium of claim 20 wherein said computer program instructions further comprise computer program instructions defining the step of calculating the normalized length of the query set according to the formula: len ⁡ ( q ) = ∑ q i ∈ q ⁢ idf ⁡ ( q i ) 2 wherein: q represents the query set; len(q) represents the normalized length of the query set; and, q i represents a specific token in q.