7. A computer program product comprising a computer readable storage medium having a computer readable program stored therein, wherein the computer readable program, when executed on a data processing system, causes the data processing system to: receive an input question from a computing device; process the input question to generate a first set of candidate answers to the input question and corresponding confidence scores for each candidate answer in the first set of candidate answers; determine whether at least one of the candidate answers in the first set of candidate answers has a corresponding confidence score equaling or exceeding a minimum confidence score value, wherein the answer to the input question is determined to not be directly provided in the corpus of information with a predetermined level of confidence if none of the candidate answers in the first set of candidate answers has a corresponding confidence score equaling or exceeding the minimum confidence score value; and in response to the answer to the input question not being directly provided in the corpus of information with the predetermined level of confidence: analyze the input question to determine whether the input question is requesting an answer that is calculable at least by: determining a domain of the input question, wherein the domain indicates a subject matter area context of the input question, and wherein the domain is one of a plurality of domains for which input questions are received by the data processing system; and invoking one or more domain specific annotators, corresponding to the determined domain, to analyze the input question, wherein the one or more domain specific annotators are configured to identify domain specific terms or phrases, specific to the determined domain of the input question, which are indicative of the answer being calculable; and in response to a determination that the input question is requesting an answer that is calculable: retrieve, from a corpus of information, one or more constituent data values for calculating the requested answer to the input question; calculate a value corresponding to the requested answer based on the one or more retrieved constituent data values; and output the calculated value as the requested answer to the input question, wherein the computer readable program causes the data processing system to calculate the value corresponding to the requested answer at least by invoking the one or more domain specific annotators to perform domain specific calculations to generate domain specific calculable values that are specific to the determined domain of the input question, and wherein different domains are associated with different sets of domain specific terms or phrases and domain specific calculable values.
11. The computer program product of claim 7 , wherein the computer readable program further causes the data processing system to analyze the input question to determine whether the input question is requesting an answer that is calculable at least by analyzing the input question to identify one or more predetermined terms or phrases corresponding to a mathematically generated value.