Nowadays, large language models (LLMs) have demonstrated their ability to be a powerful knowledge generator of generate-then-read paradigm for open-domain question answering (ODQA). However this new paradigm mainly suffers from the “hallucination” and struggles to handle time-sensitive issue because of its expensive knowledge update costs. On the other hand, retrieve-then-read, as a traditional paradigm, is more limited by the relevance of acquired knowledge to the given question. In order to combine the strengths of both paradigms, and overcome their respective shortcomings, we design a new pipeline called “FlexiQA”, in which we utilize the diverse evaluation capabilities of LLMs to select knowledge effectively and flexibly. First, given a question, we prompt a LLM as a discriminator to identify whether it is time-sensitive. For time-sensitive questions, we follow the retrieve-then-read paradigm to obtain the answer. For the non time-sensitive questions, we further prompt the LLM as an evaluator to select a better document from two perspectives: factuality and relevance. Based on the selected document, we leverage a reader to get the final answer. We conduct extensive experiments on three widely-used ODQA benchmarks, the experimental results fully confirm the effectiveness of our approach.

Explaining black-box model behavior with natural language has achieved impressive results in various NLP tasks. Recent research has explored the utilization of subsequences from the input text as a rationale, providing users with evidence to support the model decision. Although existing frameworks excel in generating high-quality rationales while achieving high task performance, they neglect to account for the unreliable link between the generated rationale and model decision. In simpler terms, a model may make correct decisions while attributing wrong rationales, or make poor decisions while attributing correct rationales. To mitigate this issue, we propose a unified two-stage framework known as Self-Attribution and Decision-Making (SADM). Through extensive experiments on five reasoning datasets from the ERASER benchmark, we demonstrate that our framework not only establishes a more reliable link between the generated rationale and model decision but also achieves competitive results in task performance and the quality of rationale. Furthermore, we explore the potential of our framework in semi-supervised scenarios.

In open-domain dialogue generation tasks, contexts and responses in most datasets are one-to-one mapped, violating an important many-to-many characteristic: a context leads to various responses, and a response answers multiple contexts. Without such patterns, models poorly generalize and prefer responding safely. Many attempts have been made in either multi-turn settings from a one-to-many perspective or in a many-to-many perspective but limited to single-turn settings. The major challenge to many-to-many augment multi-turn dialogues is that discretely replacing each turn with semantic similarity breaks fragile context coherence. In this paper, we propose DialoGue Path Sampling (DialoGPS) method in continuous semantic space, the first many-to-many augmentation method for multi-turn dialogues. Specifically, we map a dialogue to our extended Brownian Bridge, a special Gaussian process. We sample latent variables to form coherent dialogue paths in the continuous space. A dialogue path corresponds to a new multi-turn dialogue and is used as augmented training data. We show the effect of DialoGPS with both automatic and human evaluation.