Abstract
Variational autoencoders (VAEs) combine latent variables with amortized variational inference, whose optimization usually converges into a trivial local optimum termed posterior collapse, especially in text modeling. By tracking the optimization dynamics, we observe the encoder-decoder incompatibility that leads to poor parameterizations of the data manifold. We argue that the trivial local optimum may be avoided by improving the encoder and decoder parameterizations since the posterior network is part of a transition map between them. To this end, we propose Coupled-VAE, which couples a VAE model with a deterministic autoencoder with the same structure and improves the encoder and decoder parameterizations via encoder weight sharing and decoder signal matching. We apply the proposed Coupled-VAE approach to various VAE models with different regularization, posterior family, decoder structure, and optimization strategy. Experiments on benchmark datasets (i.e., PTB, Yelp, and Yahoo) show consistently improved results in terms of probability estimation and richness of the latent space. We also generalize our method to conditional language modeling and propose Coupled-CVAE, which largely improves the diversity of dialogue generation on the Switchboard dataset.- Anthology ID:
- 2020.acl-main.316
- Volume:
- Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics
- Month:
- July
- Year:
- 2020
- Address:
- Online
- Editors:
- Dan Jurafsky, Joyce Chai, Natalie Schluter, Joel Tetreault
- Venue:
- ACL
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 3449–3464
- Language:
- URL:
- https://aclanthology.org/2020.acl-main.316
- DOI:
- 10.18653/v1/2020.acl-main.316
- Cite (ACL):
- Chen Wu, Prince Zizhuang Wang, and William Yang Wang. 2020. On the Encoder-Decoder Incompatibility in Variational Text Modeling and Beyond. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, pages 3449–3464, Online. Association for Computational Linguistics.
- Cite (Informal):
- On the Encoder-Decoder Incompatibility in Variational Text Modeling and Beyond (Wu et al., ACL 2020)
- PDF:
- https://preview.aclanthology.org/nschneid-patch-4/2020.acl-main.316.pdf
- Code
- ChenWu98/Coupled-VAE