# ParaBank: Monolingual Bitext Generation and Sentential Paraphrasing via Lexically-constrained Neural Machine Translation

Source: [ParaBank: Monolingual Bitext Generation and Sentential Paraphrasing via Lexically-constrained Neural Machine Translation](<https://www.sota2.com/research/paper/68fa65501e209131cea0995d>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-25T21:23:52.793Z

Authors: J. Edward Hu, Rachel Rudinger, Matt Post, Benjamin Van Durme

Published: 2019-01-11T16:42:43.000Z

## Abstract

We present ParaBank, a large-scale English paraphrase dataset that surpasses prior work in both quantity and quality. Following the approach of ParaNMT, we train a Czech-English neural machine translation (NMT) system to generate novel paraphrases of English reference sentences. By adding lexical constraints to the NMT decoding procedure, however, we are able to produce multiple high-quality sentential paraphrases per source sentence, yielding an English paraphrase resource with more than 4 billion generated tokens and exhibiting greater lexical diversity. Using human judgments, we also demonstrate that ParaBank's paraphrases improve over ParaNMT on both semantic similarity and fluency. Finally, we use ParaBank to train a monolingual NMT model with the same support for lexically-constrained decoding for sentence rewriting tasks.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

- [Paraphrase Semantic Similarity on Human Evaluation 300 samples (random sample)](<https://www.sota2.com/research/sota/paraphrase-semantic-similarity-on-human-evaluation-300-samples-random-sample.md>): Paraphrase Semantic Similarity; Human Evaluation 300 samples (random sample); Score 3: 26.8.

- [Paraphrase Syntactic Diversity on Human Evaluation 300 samples (random sample)](<https://www.sota2.com/research/sota/paraphrase-syntactic-diversity-on-human-evaluation-300-samples-random-sample.md>): Paraphrase Syntactic Diversity; Human Evaluation 300 samples (random sample); Score 3 (%): 0.151.

- [Paraphrase Similarity and Diversity Evaluation on Shared subset of 193,869 source sentences (PARANMT, PARABANK, PARAAMR)](<https://www.sota2.com/research/sota/paraphrase-similarity-and-diversity-evaluation-on-shared-subset-of-193-869-source-sentences-paranmt-parabank-paraamr.md>): Paraphrase Similarity and Diversity Evaluation; Shared subset of 193,869 source sentences (PARANMT, PARABANK, PARAAMR); Semantic Similarity: 81.77.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/1901.03644>)

[PDF](<https://arxiv.org/pdf/1901.03644.pdf>)