Self-Consistent Decoding for More Factual Open Responses
Christopher Malon Xiaodan Zhu
Self-consistency has emerged as a powerful method for improving the accuracy
of short answers generated by large language models. As previously defined, it
only concerns the accuracy of a final answer parsed from generated text. In
this work, we extend the idea to open response generation, by integrating
voting into the decoding method. Each output sentence is selected from among
multiple samples, conditioning on the previous selections, based on a simple
token overlap score. We compare this "Sample & Select" method to greedy
decoding, beam search, nucleus sampling, and the recently introduced
hallucination avoiding decoders of DoLA, P-CRR, and S-CRR. We show that Sample
& Select improves factuality by a 30% relative margin against these decoders in
NLI-based evaluation on the subsets of CNN/DM and XSum used in the FRANK
benchmark, while maintaining comparable ROUGE-1 F1 scores against reference
summaries. We collect human verifications of the generated summaries,
confirming the factual superiority of our method.