Statistical QA - classifier vs. re-ranker

In this paper, we show that we can obtain a good baseline performance for Question Answering (QA) by using only 4 simple features. Using these features, we contrast two approaches used for a Maximum Entropy based QA system. We view the QA problem as a classification problem and as a re-ranking problem. Our results indicate that the QA system viewed as a re-ranker clearly outperforms the QA system used as a classifier. Both systems are trained using the same data.