18. The system of claim 17 , wherein computing the score for each candidate entity text string of the plurality of candidate entity text strings for the document comprises: receiving an initial score for the candidate entity text string; and determining whether the candidate entity text string occurs in a title of the document; and computing the score for the candidate entity text string including increasing the initial score for the candidate entity text string if the candidate entity text string occurs in the title of the document.
18. The system of claim 17 , wherein computing the score for each candidate entity text string of the plurality of candidate entity text strings for the document comprises: receiving an initial score for the candidate entity text string; and determining whether the candidate entity text string occurs in a title of the document; and computing the score for the candidate entity text string including increasing the initial score for the candidate entity text string if the candidate entity text string occurs in the title of the document. 19. The system of claim 18 , wherein the initial score for the candidate entity text string represents an inverse document frequency score for each term in the candidate entity text string.