Question Answering (QA) systems are of-ten built modularly, with a text retrieval component feeding forward into an answer extraction component. Conventional wis-dom suggests that, the higher the quality of the retrieval results used as input to the an-swer extraction module, the better the ex-tracted answers, and hence system accu-racy, will be. This turns out to be a poor assumption, because
... [Show full abstract] text retrieval and an-swer extraction are tightly coupled. Im-provements in retrieval quality can be lost at the answer extraction module, which can not necessarily recognize the additional answer candidates provided by improved retrieval. Going forward, to improve ac-curacy on the QA task, systems will need greater coordination between text retrieval and answer extraction modules.