Language understanding involves processing text with both the grammatical and 2 common-sense contexts of the text fragments. The text “I went to the grocery store 3 and brought home a car” requires both the grammatical context (syntactic) and 4 common-sense context (semantic) to capture the oddity in the sentence. Contex5 tualized text representations learned by Language Models (LMs) are expected to 6 capture a variety of syntactic and semantic contexts from large amounts of training 7 data corpora. Recent work such as ERNIE has shown that infusing the knowl8 edge contexts, where they are available in LMs, results in significant performance 9 gains on General Language Understanding (GLUE) benchmark tasks. However, 10 to our knowledge, no knowledge-aware model has attempted to infuse knowledge 11 through top-down semantics-driven syntactic processing (Eg: Common-sense to 12 Grammatical) and directly operated on the attention mechanism that LMs leverage 13 to learn the data context. We propose a learning framework Top-Down Language 14 Representation (TDLR) to infuse common-sense semantics into LMs. In our 15 implementation, we build on BERT for its rich syntactic knowledge and use the 16 knowledge graphs ConceptNet and WordNet to infuse semantic knowledge.
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On the Robustness of Language Encoders against Grammatical Errors
We conduct a thorough study to diagnose the behaviors of pre-trained language encoders (ELMo, BERT, and RoBERTa) when confronted with natural grammatical errors. Specifically, we collect real grammatical errors from non-native speakers and conduct adversarial attacks to simulate these errors on clean text data. We use this approach to facilitate debugging models on downstream applications. Results confirm that the performance of all tested models is affected but the degree of impact varies. To interpret model behaviors, we further design a linguistic acceptability task to reveal their abilities in identifying ungrammatical sentences and the position of errors. We find that fixed contextual encoders with a simple classifier trained on the prediction of sentence correctness are able to locate error positions. We also design a cloze test for BERT and discover that BERT captures the interaction between errors and specific tokens in context. Our results shed light on understanding the robustness and behaviors of language encoders against grammatical errors.
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- Award ID(s):
- 1927554
- NSF-PAR ID:
- 10192196
- Date Published:
- Journal Name:
- Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics
- Page Range / eLocation ID:
- 3386 to 3403
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.18653/v1/2020.acl-main.310
