FUDGE: Controlled Text Generation With Future Discriminators
Kevin Yang, Dan Klein · 2021
We propose Future Discriminators for Generation (FUDGE), a flexible and modular method for controlled text generation.Given a preexisting model G for generating text from a distribution of interest, FUDGE enables conditioning on a desired attribute a (for example, formality) while requiring access only to G's output logits.FUDGE learns an attribute predictor operating on a partial sequence, and uses this predictor's outputs to adjust G's original probabilities.We show that FUDGE models terms corresponding to a Bayesian decomposition of the conditional distribution of G given attribute a.Moreover, FUDGE can easily compose predictors for multiple desired attributes.We evaluate FUDGE on three tasks -couplet completion in poetry, topic control in language generation, and formality change in machine translation -and observe gains in all three tasks.