6. The method of claim 1 further comprising the step of calculating the idf weight of a specific token according to the formula: 
 idf ( q i )=log 2 (1 +N/N ( q i )) wherein: q i represents the specific token; idf(q i ) represents the idf weight of the specific token; N represents the total number of database sets in the data collection set; and, N(q i ) represents the number of database sets that contain the token q i .
6. The method of claim 1 further comprising the step of calculating the idf weight of a specific token according to the formula: 
 idf ( q i )=log 2 (1 +N/N ( q i )) wherein: q i represents the specific token; idf(q i ) represents the idf weight of the specific token; N represents the total number of database sets in the data collection set; and, N(q i ) represents the number of database sets that contain the token q i . 7. The method of claim 6 further comprising the step of calculating the normalized length of the first database set according to the formula: len ⁡ ( s ) = ∑ s i ∈ s ⁢ idf ⁡ ( s i ) 2 wherein: s represents the first database set; len(s) represents the normalized length of the first database set; and, s i represents a specific token in s.