Generating an answer from multiple pipelines using clustering

Mechanisms for generating an answer to an input question are provided. The mechanisms receive an input question and route the input question to a plurality of Question and Answer (QA) system pipelines. The mechanisms receive results of processing the input question from each QA system pipeline in the plurality of QA system pipelines. The results comprise one or more candidate answers to the input question and associated confidence scores. The mechanisms adjust, for each QA system pipeline, the confidence scores of the one or more candidate answers associated with the QA system pipeline based on one or more weighting factors. In addition, the mechanisms generate the answer to the input question based on the adjusted confidence scores of the one or more candidate answers for each QA system pipeline.