22. The at least one computer readable memory of claim 16 , wherein the external knowledge source includes a calendar with date information and during the analyzing of the plurality of interpretations, and wherein the method further comprises the at least one processor comparing at least one information item in the plurality of information items for each of the plurality of interpretations with the calendar to detect if any invalid date combinations are present in the at least one information item.
16. At least one computer readable memory encoded with a plurality of instructions that, when executed, perform a method of improving speech recognition, the method comprising: receiving a speech recognition result from an automatic speech recognition (ASR) engine, the speech recognition result including a plurality of ordered interpretations, wherein each of the ordered interpretations includes a plurality of information items; and analyzing the plurality of interpretations using an external knowledge source to create a filtered plurality of ordered interpretations; wherein the external knowledge source includes a position location information, and during the analyzing of the plurality of interpretations, the at least one processor determines if any of the plurality of information items relate to travel requests, and if so, adds the position location information to each information item of the plurality of information items relating to travel.