Mechanisms for selecting questions for a cluster of questions to be used with a question and answer (QA) system are provided. An input question is received and analyzed to identify at least one feature of the input question. Clustering of the input question with one or more other questions in a cluster of questions based on the at least one feature of the input question is performed. Based on results of the clustering, a determination is made as to whether to include or reject the input question as part of the cluster of questions. In response to determining to include the input question as part of the cluster of questions, the cluster of questions is updated to include the input question. The updated cluster of questions is stored in a storage device associated with a data processing system.