Therefore, we have: Therefore, for a given post X and its ground- ), optimizing CVaR is equivalent to maximizing the following objective function: where Y 1−α is a collection of ground-truth responses such that: We can see that maximizing the above objective function requires the worst 1 − α responses to be close to the post.
we aim to capture each distinct post-response matching pattern by optimizing the CVaR criteria, which can meet the requirement for generating diverse responses.