1. A computer-implemented method comprising: selecting a target word from a set of words from a plurality of documents; determining a first subset of words from the set comprising words that are most correlated with the target word; determining a set of values, wherein each value is associated with a correlation between a first word from the first subset and a second word from the first subset, wherein the first word and the second word co-occur with the target word in a document of a plurality of documents; and determining, based on the set of values, at least two clusters of words from the first subset; assigning weights to words in the first subset of words based on the at least two determined clusters; determining a second subset of words that occur in a particular document and correspond to words in the first subset of words, wherein the particular document has the target word; based on the weights of words in the first subset of words that correspond to the second subset of words, selecting, for the particular document, a cluster of the at least two clusters; refining the weights of words in the first subset of words based on the selected cluster; wherein at least the steps of determining the set of values, selecting the cluster, and refining the weights are performed by one or more computing devices.
1. A computer-implemented method comprising: selecting a target word from a set of words from a plurality of documents; determining a first subset of words from the set comprising words that are most correlated with the target word; determining a set of values, wherein each value is associated with a correlation between a first word from the first subset and a second word from the first subset, wherein the first word and the second word co-occur with the target word in a document of a plurality of documents; and determining, based on the set of values, at least two clusters of words from the first subset; assigning weights to words in the first subset of words based on the at least two determined clusters; determining a second subset of words that occur in a particular document and correspond to words in the first subset of words, wherein the particular document has the target word; based on the weights of words in the first subset of words that correspond to the second subset of words, selecting, for the particular document, a cluster of the at least two clusters; refining the weights of words in the first subset of words based on the selected cluster; wherein at least the steps of determining the set of values, selecting the cluster, and refining the weights are performed by one or more computing devices. 2. The method as recited in claim 1 , further comprising: establishing a first cluster as being associated with a first meaning of the target word; and establishing a second cluster as being associated with a second meaning of the target word.