Learning to Paraphrase for Question Answering
Table 6: Questions and their top-five paraphrases with probabilities learned by the model. The Freebase relations used to query the correct answers are shown in brackets. The original question is underlined. Questions with incorrect predictions are in myredred.
['[BOLD] Examples', '[ITALIC] pθ( [ITALIC] q′| [ITALIC] q)']
Examples of paraphrases and their probabilities pθ(q′|q) The two examples are taken from the development set of GraphQuestions and WebQuestions, respectively. We also show the Freebase relations used to query the correct answers. In the first example, the original question cannot yield the correct answer because of the mismatch between the question and the knowledge base. The paraphrase contains “role” in place of “sort of part”, increasing the chance of overlap between the question and the predicate words. The second question contains an informal expression “play 4”, which confuses the QA model. The paraphrase model generates “play for” and predicts a high paraphrase score for it. More generally, we observe that the model tends to give higher probabilities pθ(q′|q) to paraphrases biased towards delivering appropriate answers.