46. The method of claim 45 , wherein gathering switching data comprises gathering context data for other terms located in proximity to query terms or query phrases in previous queries; and wherein generating the probabilities of switching between query phrases comprises using the context data to consider conditional probabilities.
45. The method of claim 44 , wherein gathering switching data from previous queries comprises: identifying possible query phrases from the previous queries; and generating probabilities of switching between query phrases based on patterns observed in the previous queries; wherein the switching probabilities are used to determine whether a switched query phrase will be considered as a candidate synonym for a query phrase.