The Verified Query Repository: A Human-in-the-Loop Architectural Pattern for Eliminating Hallucination in Enterprise NLP Systems

Abstract

Enterprise deployments of large language model-powered natural language processing systems produce a class of failure that is systematically more damaging than errors that surface visibly. The response is fluent. It is confident. And it is factually wrong, consumed by decision-makers who have no mechanism to detect the error before it propagates through organizational processes. Existing mitigation strategies, including prompt engineering, retrieval-augmented generation, and fine-tuning, reduce the probability of this failure without providing structural guarantees for the specific queries where reliability is non-negotiable. This paper introduces the Verified Query Repository (VQR), a human-in-the-loop architectural pattern that addresses hallucination in enterprise NLP systems by replacing generation with retrieval for high-stakes queries whose responses have been previously validated by human domain experts. The VQR stores curated, human-approved query-response pairs with provenance metadata, similarity-matched against incoming queries at runtime. Queries exceeding a defined similarity threshold retrieve the validated response directly, bypassing large language model inference for that query class. The paper presents the VQR entry schema, query routing architecture, human validation workflow, and staleness management framework, alongside a governance model covering ownership structures, curation quality standards, and coverage expansion strategies. VQR reliability depends on curation quality and staleness management rather than model capability. Organizations deploying VQR without the governance infrastructure to sustain it will find the repository degrades at the pace that business change imposes. VQR is positioned as a complement to retrieval-augmented generation, providing structural reliability guarantees for high-stakes query classes that probabilistic mitigation approaches cannot deliver.