Toward a Theory of Causation for Interpreting Neural Code Models
| Title: | Toward a Theory of Causation for Interpreting Neural Code Models |
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| Authors: | Palacio, David N., Velasco, Alejandro, Cooper, Nathan, Rodriguez, Alvaro, Moran, Kevin, Poshyvanyk, Denys |
| Publication Year: | 2023 |
| Collection: | Computer Science Statistics |
| Subject Terms: | Computer Science - Software Engineering, Computer Science - Artificial Intelligence, Computer Science - Machine Learning, Statistics - Methodology |
| More Details: | Neural Language Models of Code, or Neural Code Models (NCMs), are rapidly progressing from research prototypes to commercial developer tools. As such, understanding the capabilities and limitations of such models is becoming critical. However, the abilities of these models are typically measured using automated metrics that often only reveal a portion of their real-world performance. While, in general, the performance of NCMs appears promising, currently much is unknown about how such models arrive at decisions. To this end, this paper introduces $do_{code}$, a post hoc interpretability method specific to NCMs that is capable of explaining model predictions. $do_{code}$ is based upon causal inference to enable programming language-oriented explanations. While the theoretical underpinnings of $do_{code}$ are extensible to exploring different model properties, we provide a concrete instantiation that aims to mitigate the impact of spurious correlations by grounding explanations of model behavior in properties of programming languages. To demonstrate the practical benefit of $do_{code}$, we illustrate the insights that our framework can provide by performing a case study on two popular deep learning architectures and ten NCMs. The results of this case study illustrate that our studied NCMs are sensitive to changes in code syntax. All our NCMs, except for the BERT-like model, statistically learn to predict tokens related to blocks of code (\eg brackets, parenthesis, semicolon) with less confounding bias as compared to other programming language constructs. These insights demonstrate the potential of $do_{code}$ as a useful method to detect and facilitate the elimination of confounding bias in NCMs. Comment: Accepted to appear in IEEE Transactions on Software Engineering |
| Document Type: | Working Paper |
| DOI: | 10.1109/TSE.2024.3379943 |
| Access URL: | http://arxiv.org/abs/2302.03788 |
| Accession Number: | edsarx.2302.03788 |
| Database: | arXiv |
| DOI: | 10.1109/TSE.2024.3379943 |
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