Promptriever: Instruction-Trained Retrievers Can Be Prompted Like Language Models
Orion Weller, Benjamin Van Durme, Dawn Lawrie, Ashwin Paranjape, Yuhao Zhang, Jack Hessel
TL;DR
<3-5 sentence high-level summary> Promptriever introduces a promptable dense retriever trained on a large, instruction-focused MS MARCO augmentation, enabling per-query instruction control over relevance. It demonstrates strong instruction-following capabilities, competitive standard retrieval, and reliable gains when prompted at test time, bridging LM prompting methods with information retrieval. The work shows that instruction negatives and joint MS MARCO data significantly contribute to learning to condition relevance on natural language instructions, and that prompts can meaningfully improve out-of-domain retrieval. Overall, it paves the way for controllable, instruction-driven retrieval and cross-pollination between LM prompting and IR research.
Abstract
Instruction-tuned language models (LM) are able to respond to imperative commands, providing a more natural user interface compared to their base counterparts. In this work, we present Promptriever, the first retrieval model able to be prompted like an LM. To train Promptriever, we curate and release a new instance-level instruction training set from MS MARCO, spanning nearly 500k instances. Promptriever not only achieves strong performance on standard retrieval tasks, but also follows instructions. We observe: (1) large gains (reaching SoTA) on following detailed relevance instructions (+14.3 p-MRR / +3.1 nDCG on FollowIR), (2) significantly increased robustness to lexical choices/phrasing in the query+instruction (+12.9 Robustness@10 on InstructIR), and (3) the ability to perform hyperparameter search via prompting to reliably improve retrieval performance (+1.4 average increase on BEIR). Promptriever demonstrates that retrieval models can be controlled with prompts on a per-query basis, setting the stage for future work aligning LM prompting techniques with information retrieval.
