Weaver: Foundation Models for Creative Writing

TL;DR

Weaver is a family of specialized large language models optimized for creative and professional writing, outperforming larger generalist models like GPT-4 in writing tasks, with capabilities for retrieval augmentation and tool integration.

Contribution

Introduces Weaver, a new family of domain-specific LLMs for content creation, with novel training, fine-tuning, and alignment methods tailored for high-quality writing.

Findings

Weaver models outperform larger generalist LLMs on writing benchmarks.

Weaver Ultra surpasses GPT-4 in various writing scenarios.

Supports retrieval-augmented generation and tool calling for enhanced writing assistance.

Abstract

This work introduces Weaver, our first family of large language models (LLMs) dedicated to content creation. Weaver is pre-trained on a carefully selected corpus that focuses on improving the writing capabilities of large language models. We then fine-tune Weaver for creative and professional writing purposes and align it to the preference of professional writers using a suit of novel methods for instruction data synthesis and LLM alignment, making it able to produce more human-like texts and follow more diverse instructions for content creation. The Weaver family consists of models of Weaver Mini (1.8B), Weaver Base (6B), Weaver Pro (14B), and Weaver Ultra (34B) sizes, suitable for different applications and can be dynamically dispatched by a routing agent according to query complexity to balance response quality and computation cost. Evaluation on a carefully curated benchmark for assessing the writing capabilities of LLMs shows Weaver models of all sizes outperform generalist LLMs several times larger than them. Notably, our most-capable Weaver Ultra model surpasses GPT-4, a state-of-the-art generalist LLM, on various writing scenarios, demonstrating the advantage of training specialized LLMs for writing purposes. Moreover, Weaver natively supports retrieval-augmented generation (RAG) and function calling (tool usage). We present various use cases of these abilities for improving AI-assisted writing systems, including integration of external knowledge bases, tools, or APIs, and providing personalized writing assistance. Furthermore, we discuss and summarize a guideline and best practices for pre-training and fine-tuning domain-specific LLMs.