RewriteLM: An Instruction-Tuned Large LanguageModel for Text Rewriting

In recent years, Large Language Models (LLMs) have demonstrated impressive zero-shot capabilities in text generation tasks expressed through natural language instructions. However, text rewriting is a challenging task, and unintended modifications can negatively impact the system's performance. To address this challenge, we introduce a novel benchmark for text rewriting that covers a wide variety of rewriting types expressed through natural language instructions. Unlike previous benchmarks, which were primarily focused on limited rewrite styles and sentence-level rewriting, our benchmark is specifically designed to facilitate open-ended rewriting of long-form text. Additionally, we present a strong baseline model, RewriteLM, which is an instruction-tuned large language model for text rewriting. The model is trained using supervised fine-tuning, reward training, and reinforcement learning. To minimize human intervention in the data collection process, we develop new data generation strategies: (1) utilizing high-quality, long-form edits from Wikipedia as our primary natural training data source, (2) generating a synthetic dataset that includes diverse edit types and non-Wiki domains using chain-of-thoughts and the capabilities of LLMs, and (3) employing human-designed heuristic rankers to generate preference data. Our experiments demonstrate the effectiveness of our proposed benchmark and baseline model, as well as the benefits of our data collection strategies in minimizing human intervention.