9. The computer program product of claim 1 , including: sequentially applying the equation c i =s i +a×r ij ×c j to pairs of the plurality of the electronic documents.
9. The computer program product of claim 1 , including: sequentially applying the equation c i =s i +a×r ij ×c j to pairs of the plurality of the electronic documents. 12. The computer program product according to claim 9 , wherein 0 < assigned weights <1.