1. A system for updating a partial dialog state, the system configured to: receive user input at a first turn; generate a semantic representation based on the user input at the first turn; generate a partial dialog state based in part on the semantic representation associated with the first turn; receive user input at a second turn; generate the semantic representation based on the user input at the second turn; update the partial dialog state for the second turn using a discriminative model using the semantic representation associated with the first turn and the second turn, wherein the partial dialog state is based on a time ordered sequence of an estimated user goal; and based in part on the partial dialog state, determining a dialog state as part of tracking a user goal.