A call routing system prompts a caller for information and receives a response from the caller. Based on the caller's response, a confidence value is assigned to the call. The confidence value can be assigned based on the likelihood that the received information is consistent with the prompt and other criteria. Additional prompts are provided to the caller based on the confidence value, and additional caller's responses are used to modify the confidence value. At least one threshold confidence level is set and when the confidence value of the call meets or exceeds the threshold (because of low confidence), the call is immediately routed to a human operator.