Training task-oriented dialogue systems typically requires turn-level annotations for interacting with their APIs: e.g. a dialogue state and the system actions taken at each step. These annotations can be costly to produce, error-prone, and require both domain and annotation expertise. With advances in LLMs, we hypothesize unlabelled data and a schema definition are sufficient for building a working task-oriented dialogue system, completely unsupervised. Using only (1) a well-defined API schema (2) a set of unlabelled dialogues between a user and agent, we develop a novel approach for inferring turn-level annotations as latent variables using a noisy channel model. We iteratively improve these pseudo-labels with expectation-maximization (EM), and use the inferred labels to train an end-to-end dialogue agent. Evaluating our approach on the MultiWOZ benchmark, our method more than doubles the dialogue success rate of a strong GPT-3.5 baseline.

通过使用未标注的数据和模式定义，我们开发了一种新方法来构建一个完全无监督的面向任务的对话系统，该系统可以在迭代中通过期望最大化方法逐渐改进伪标签，并利用这些标签来训练一个端到端的对话代理，其在MultiWOZ基准测试上的成功率超过了强大的GPT-3.5基准的两倍。

嘈杂信道的力量：无监督端到端任务导向对话的LLMs