Existing conversational systems are mostly agent-centric, which assumes the user utterances would closely follow the system ontology (for NLU or dialogue state tracking). However, in real-world scenarios, it is highly desirable that the users can speak freely in their own way. It is extremely hard, if not impossible, for the users to adapt to the unknown system ontology. In this work, we attempt to build a user-centric dialogue system. As there is no clean mapping for a user's free form utterance to an ontology, we first model the user preferences as estimated distributions over the system ontology and map the users' utterances to such distributions. Learning such a mapping poses new challenges on reasoning over existing knowledge, ranging from factoid knowledge, commonsense knowledge to the users' own situations. To this end, we build a new dataset named NUANCED that focuses on such realistic settings for conversational recommendation. Collected via dialogue simulation and paraphrasing, NUANCED contains 5.1k dialogues, 26k turns of high-quality user responses. We conduct experiments, showing both the usefulness and challenges of our problem setting. We believe NUANCED can serve as a valuable resource to push existing research from the agent-centric system to the user-centric system. The code and data is publicly available at \url{https://github.com/facebookresearch/nuanced}.
翻译:现有对话系统大多以代理为中心, 假设用户的语句将密切遵循系统文理学( 用于NLU或对话状态跟踪) 。 然而, 在现实世界的情景下, 用户最好能够以自己的方式自由发言。 用户要适应未知的系统文理学是极其困难的, 如果不是不可能的话, 用户要适应未知的系统文理学。 在这项工作中, 我们试图建立一个以用户为中心的对话系统。 由于用户的自由形式表达对本体学没有干净的映射, 我们首先将用户的偏好作为系统本( 用于NLU或对话状态跟踪 ) 。 但是, 在实际世界的情景下, 用户的言语表达方式非常理想。 学习这样的映像对现有知识的推理提出了新的挑战, 从事实知识、 普通知识到用户自身的情况。 为此, 我们建立一个名为 NUSCD 的新数据集, 侧重于这种现实的环境建议。 通过对话模拟和语音表达, NUSCD 包含 5ak 对话, 26k 高品质用户反应的转换。 我们进行实验, 既显示可使用又挑战的用户核心研究系统。 我们相信, 也是现有的数据库。