deltaBLEU: A Discriminative Metric for Generation Tasks with Intrinsically Diverse Targets

Understand

We introduce Discriminative BLEU (deltaBLEU), a novel metric for intrinsic evaluation of generated text in tasks that admit a diverse range of possible outputs.

• Reference strings are scored for quality by human raters on a scale of [-1, +1] to weight multi-reference BLEU.
• In tasks involving generation of conversational responses, deltaBLEU correlates reasonably with human judgments and outperforms sentence-level and IBM BLEU in terms of both Spearman's rho and Kendall's tau.