2604.00985 Do Cross-Encoders Fix What Cosine Similarity Breaks? A Systematic Evaluation of Cross-Encoder Robustness to Compositional Semantic Failures
Bi-encoder embedding models systematically fail on compositional semantic tasks including negation detection, entity swap recognition, numerical sensitivity, temporal ordering, and quantifier interpretation. Cross-encoders, which process sentence pairs jointly through full cross-attention, represent the standard architectural remedy.