7. The computer-implemented method of claim 1 , wherein generating the signature value that describes the second word positions relative to the first word position comprises calculating, for second word positions within the plurality of second word positions, an angle between the first word position and the second word position.
7. The computer-implemented method of claim 1 , wherein generating the signature value that describes the second word positions relative to the first word position comprises calculating, for second word positions within the plurality of second word positions, an angle between the first word position and the second word position. 9. The computer-implemented method of claim 7 , wherein generating the signature value that describes the second word positions relative to the first word position further comprises: concatenating the calculated angles; and discretizing the calculated angles prior to concatenation.