2. A method for configuring a natural language (NL) understanding system, the NL understanding system including at least a linguistic classifier, the linguistic classifier being configurable with configuration data to distinguish a plurality of linguistic categories based on a linguistic input, the method comprising: configuring the linguistic classifier with first configuration data; processing a second plurality of user inputs to the system, wherein the processing includes, for each of the second plurality of user inputs, using the linguistic classifier configured with the first configuration data to determine a recognized linguistic category corresponding to said input, and causing determination of a corresponding response to the input based on the recognized linguistic category; storing second collected data, the second collected data comprising, for each of the second plurality of user inputs, a representation of the user input and the corresponding responses; receiving annotations for the second collected data, an annotation for each item of the second collected data indicating whether the corresponding response is consistent with the user input; determining second configuration data for the first linguistic classifier, the second configuration data being determined to distinguish the plurality of linguistic categories by computing the second configuration data to match the second annotated data; and configuring the linguistic classifier with the second configuration data.
5. The method of claim 2 further comprising determining the first configuration data including receiving first annotated data, the first annotated data associating each user input of a plurality of user input of first collected data with a corresponding linguistic category of the plurality of categories; and computing the first configuration data for the first linguistic classifier to distinguish the plurality of linguistic categories by selecting the first configuration data to match the first annotated data.