  Self-consistency with chain-of-thought prompting (CoT) has demonstrated
remarkable performance gains on various challenging tasks, by utilizing
multiple reasoning paths sampled from large language models (LLMs). However,
self-consistency relies on the answer extraction process to aggregate multiple
solutions, which is not applicable to free-form answers. In this work, we
propose Universal Self-Consistency (USC), which leverages LLMs themselves to
select the most consistent answer among multiple candidates. We evaluate USC on
a variety of benchmarks, including mathematical reasoning, code generation,
long-context summarization, and open-ended question answering. On open-ended
generation tasks where the original self-consistency method is not applicable,
USC effectively utilizes multiple samples and improves the performance. For
mathematical reasoning, USC matches the standard self-consistency performance
without requiring the answer formats to be similar. Finally, without access to
execution results, USC also matches the execution-based voting performance on
code generation.
