For our first backoff level, we introduce a novel way to generalize over the verb, slot, and noun information of Here we use a linear interpolation of three probabilities, each of which: (1) drops one source of conditioning information from the most specific probability, and (2) generalizes a second source of conditioning information to a class-based conditioning event.
we use the following probability formula: is verb class, and the individual probabilities are (currently) equally weighted (i.e., all , the noun component is dropped, and the slot is generalized to the appropriate slot class.