6. A computer-implemented method of determining whether a business listing is legitimate, the method comprising: accessing, by a processor, a list of legitimate business titles, each legitimate business title including one or more words; generating a matrix of surprisingness values, where each surprisingness value indicates a likelihood of a word appearing in a legitimate business title, by: examining each legitimate business title to identify pairs of words occurring in that title, adding a count value to the matrix for each pair of words identified, such that the matrix includes a plurality of count values for different pairs of words occurring in the legitimate business titles, and normalizing the plurality of count values for the matrix to generate the matrix of surprisingness values, where each surprisingness value of the matrix of surprisingness values indicates how likely a pair of words are to appear in a legitimate business title; storing the matrix of surprisingness values in memory; accessing a first plurality of business listings each associated with title data including two or more words; identifying, from the first plurality of business listings, a second plurality of business listings all corresponding to one particular business; for each business listing of the identified second plurality of business listings, determining a surprisingness value indicative of the surprisingness of the title included in the particular business listing based on the stored matrix of surprisingness values; determining an average surprisingness value for the identified second plurality of business listings based on the stored matrix of surprisingness values; selecting a particular business listing of the identified second plurality of business listings; and determining whether the particular business listing is legitimate based on whether the surprisingness value for the particular business listing is greater than the average surprisingness value plus a threshold value.
6. A computer-implemented method of determining whether a business listing is legitimate, the method comprising: accessing, by a processor, a list of legitimate business titles, each legitimate business title including one or more words; generating a matrix of surprisingness values, where each surprisingness value indicates a likelihood of a word appearing in a legitimate business title, by: examining each legitimate business title to identify pairs of words occurring in that title, adding a count value to the matrix for each pair of words identified, such that the matrix includes a plurality of count values for different pairs of words occurring in the legitimate business titles, and normalizing the plurality of count values for the matrix to generate the matrix of surprisingness values, where each surprisingness value of the matrix of surprisingness values indicates how likely a pair of words are to appear in a legitimate business title; storing the matrix of surprisingness values in memory; accessing a first plurality of business listings each associated with title data including two or more words; identifying, from the first plurality of business listings, a second plurality of business listings all corresponding to one particular business; for each business listing of the identified second plurality of business listings, determining a surprisingness value indicative of the surprisingness of the title included in the particular business listing based on the stored matrix of surprisingness values; determining an average surprisingness value for the identified second plurality of business listings based on the stored matrix of surprisingness values; selecting a particular business listing of the identified second plurality of business listings; and determining whether the particular business listing is legitimate based on whether the surprisingness value for the particular business listing is greater than the average surprisingness value plus a threshold value. 7. The method of claim 6 , further comprising normalizing the matrix of surprisingness values before determining the surprisingness value for each business listing of the identified second plurality of business listings.