Prompts as Auto-Optimized Training Hyperparameters: Training Best-in-Class IR Models from Scratch with 10 Gold Labels

We develop a method for training small-scale (under 100M parameter) neural information retrieval models with as few as 10 gold relevance labels. The method depends on generating synthetic queries for documents using a language model (LM), and the key step is that we automatically optimize the LM prompt that is used to generate these queries based on training quality. In experiments with the BIRCO benchmark, we find that models trained with our method outperform RankZephyr and are competitive Figure 1: An overview of the PATH pipeline for training with RankLLama, both of which are 7B parameter a reranker with synthetic queries. A user only needs to models trained on over 100K labels. These input a prompt with the task description and as few as findings point to the power of automatic prompt 10 relevance judgements to achieve strong results.