Multi-document retrieval approaches often overlook the ways different retrievals complement each other when addressing complex queries. In this work, we study journalist source selection in news article writing and examine the discourse roles that different sources serve when paired together, finding that discourse function (not simply informational content) is an important component of source usage. Then, we introduce a novel IR task to benchmark how well language models can reason about this narrative process. We extract a journalist’s initial query and the sources they used from news articles and aim to recover the sources that support this query. We demonstrate that large language models (LLMs) can be employed in multi-step query planning, identifying informational gaps and enhancing retrieval performance, but current approaches to interleave queries fall short. By training auxiliary discourse planners and incorporating this information into LLMs, we enhance query planning, achieving a significant 5% improvement in precision and a 2% increase in F1 score over the previous SOTA, all while maintaining recall.

In industrial LLM development, evaluating large language models (LLMs) is critical for tasks like benchmarking internal models and detecting regressions during fine-tuning, but existing benchmark aggregation methods, such as Elo-based systems, can be resource-intensive, public facing, and time-consuming. Here, we describe Chatbot Arena Estimate (CAE), a practical framework for aggregating performance across diverse benchmarks. The framework, developed and widely adopted within our organization, addresses the need for quick, accurate, and cost-efficient evaluations of LLMs. CAE generates two primary metrics: a “Goodness” score (answer accuracy) and a “Fastness” score (cost or queries per second, QPS). These metrics allow for model ranking both overall and within specific subdomains, enabling informed decisions during model iteration and deployment. We demonstrate CAE’s effectiveness by comparing it with existing benchmarks, including the full Chatbot Arena and the MMLU leaderboard. Notably, our approach achieves higher Pearson correlation with Chatbot Arena Elo scores than MMLU’s correlation with Chatbot Arena Elo scores, validating its reliability for real-world LLM evaluation.