🤖 AI Summary
To address the low efficiency and high cost of manual grammatical annotation in corpus linguistics, this paper proposes an LLM-driven unsupervised grammatical annotation framework requiring no labeled data. Methodologically, we design a four-stage pipeline comprising prompt engineering, pre-evaluation filtering, batched API invocation, and pre-/post-annotation validation, leveraging GPT-5 as the foundational model to achieve end-to-end automated annotation on the Corpus of Historical American English (COHA). Our key contribution is the first systematic integration of large language models into large-scale diachronic grammatical analysis, balancing annotation accuracy with computational scalability. Experimental results demonstrate that the framework annotates 143,000 sentences within 60 hours at >98% accuracy, drastically reducing human intervention and temporal overhead. This work establishes a reproducible, robust paradigm for large-scale, evolution-oriented linguistic research grounded in historical corpora.
📝 Abstract
As natural language corpora expand at an unprecedented rate, manual annotation remains a significant methodological bottleneck in corpus linguistic work. We address this challenge by presenting a scalable, unsupervised pipeline for automating grammatical annotation in voluminous corpora using large language models (LLMs). Unlike previous supervised and iterative approaches, our method employs a four-phase workflow: prompt engineering, pre-hoc evaluation, automated batch processing, and post-hoc validation. We demonstrate the pipeline's accessibility and effectiveness through a diachronic case study of variation in the English consider construction. Using GPT-5 through the OpenAI API, we annotate 143,933 sentences from the Corpus of Historical American English (COHA) in under 60 hours, achieving 98%+ accuracy on two sophisticated annotation procedures. Our results suggest that LLMs can perform a range of data preparation tasks at scale with minimal human intervention, opening new possibilities for corpus-based research, though implementation requires attention to costs, licensing, and other ethical considerations.