Transformers as Graph-to-Graph Models

James Henderson, Alireza Mohammadshahi, Andrei Coman, Lesly Miculicich


Abstract
We argue that Transformers are essentially graph-to-graph models, with sequences just being a special case. Attention weights are functionally equivalent to graph edges. Our Graph-to-Graph Transformer architecture makes this ability explicit, by inputting graph edges into the attention weight computations and predicting graph edges with attention-like functions, thereby integrating explicit graphs into the latent graphs learned by pretrained Transformers. Adding iterative graph refinement provides a joint embedding of input, output, and latent graphs, allowing non-autoregressive graph prediction to optimise the complete graph without any bespoke pipeline or decoding strategy. Empirical results show that this architecture achieves state-of-the-art accuracies for modelling a variety of linguistic structures, integrating very effectively with the latent linguistic representations learned by pretraining.
Anthology ID:
2023.bigpicture-1.8
Volume:
Proceedings of the Big Picture Workshop
Month:
December
Year:
2023
Address:
Singapore
Editors:
Yanai Elazar, Allyson Ettinger, Nora Kassner, Sebastian Ruder, Noah A. Smith
Venue:
BigPicture
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
93–107
Language:
URL:
https://aclanthology.org/2023.bigpicture-1.8
DOI:
10.18653/v1/2023.bigpicture-1.8
Bibkey:
Cite (ACL):
James Henderson, Alireza Mohammadshahi, Andrei Coman, and Lesly Miculicich. 2023. Transformers as Graph-to-Graph Models. In Proceedings of the Big Picture Workshop, pages 93–107, Singapore. Association for Computational Linguistics.
Cite (Informal):
Transformers as Graph-to-Graph Models (Henderson et al., BigPicture 2023)
Copy Citation:
PDF:
https://aclanthology.org/2023.bigpicture-1.8.pdf