11. A method according to claim 10 , wherein determining category memberships for the at least two words includes determining category memberships for the at least two words along at least a content dimension and a quality dimension.
11. A method according to claim 10 , wherein determining category memberships for the at least two words includes determining category memberships for the at least two words along at least a content dimension and a quality dimension. 13. A method according to claim 11 , wherein using the category memberships for the at least two words to establish a signature for the at least two words includes: identifying communication types; determining a membership value in each communication type for each of the at least two words; and for each combination of communication types, calculating the sum of the membership numerical values for each of the at least two words in the communication types in the combination, divided by the number of non-zero membership numerical values for each of the at least two words in the communication types in the combination.