PEARL: Personalizing Large Language Model Writing Assistants with
  Generation-Calibrated Retrievers
Sheshera Mysore Zhuoran Lu Mengting Wan Longqi Yang Steve Menezes Tina Baghaee Emmanuel Barajas Gonzalez Jennifer Neville Tara Safavi
Powerful large language models have facilitated the development of writing
assistants that promise to significantly improve the quality and efficiency of
composition and communication. However, a barrier to effective assistance is
the lack of personalization in LLM outputs to the author's communication style
and specialized knowledge. In this paper, we address this challenge by
proposing PEARL, a retrieval-augmented LLM writing assistant personalized with
a generation-calibrated retriever. Our retriever is trained to select historic
user-authored documents for prompt augmentation, such that they are likely to
best personalize LLM generations for a user request. We propose two key
novelties for training our retriever: 1) A training data selection method that
identifies user requests likely to benefit from personalization and documents
that provide that benefit; and 2) A scale-calibrating KL-divergence objective
that ensures that our retriever closely tracks the benefit of a document for
personalized generation. We demonstrate the effectiveness of PEARL in
generating personalized workplace social media posts and Reddit comments.
Finally, we showcase the potential of a generation-calibrated retriever to
double as a performance predictor and further improve low-quality generations
via LLM chaining.