ResearchBenchmarksLinguistic Minimal Pair Classification on BLiMP left branch island echo questionFollow63.2AccuracyTargeted43.85648.87853.958.922Apr 20, 2026Evaluation ResultsMethodMethodLinksAccuracyPerformance Delta (Δ)Accuracy (only NPI scope)Accuracy (Existential there quantifiers)Accuracy (WH vs that long distance)Accuracy (Matrix question NPI licensor present)Accuracy (Principle A reconstruction)Accuracy (Sentential subject island)Accuracy (Left branch island echo question)Accuracy (Coordination structure constraint complex left branch)Accuracy (Principle A c-command)TargetedData Intervention Stra...Data Intervention Strategy=specific synthetic, Synthetic Data Percentage=1%2026.0463.217.9——————63.2——BaselinePre-training Corpus=10...Pre-training Corpus=100M FineWeb2026.0445.3———————45.3——RandomData Intervention Stra...Data Intervention Strategy=random synthetic, Synthetic Data Percentage=1%2026.0444.6———————44.6——