DECAF: A Dynamically Extensible Corpus Analysis Framework

The study of generalization in Language Models (LMs) requires controlled experiments that can precisely measure complex linguistic variations between training and testing datasets.We introduce DECAF, a framework that enables the analysis and filtering of linguisticallyannotated datasets down to the character level.Rather than creating new resources for each experiment, DECAF starts from datasets with existing linguistic annotations, and leverages them to analyze, filter, and generate highly controlled and reproducible experimental settings targeting specific research questions.We demonstrate DECAF's functionality by adding 28 morphosyntactic annotation layers to the 115M-word BabyLM corpus and indexing the resulting 1.1B annotations to analyze its internal domain variance, and to create a controlled training data curriculum for a small-scale gender bias study.We release DECAF as an opensource Python library, along with the parsed and indexed version of BabyLM, as resources for future generalization research.