7. The method as recited in claim 5 , wherein the generation parameters for a given source include, a probability α s that the given source, when asked to construct a text instance, picks a word from a true title, and a probability β s that the given source, when asked to construct the text instance, picks a word from the context webpage.
8. The method as recited in claim 7 , wherein computing a likelihood further includes, calculating a word probability that a source generates a specific text instance as a sum of, α s multiplied by a number of times the specific text instance is in the true title divided by a size of the true title, β s multiplied by a number of times the specific text instance is in the context webpage divided by a size of the context webpage, and (1−α s −β s ) divided by a size of a vocabulary of all possible words.