Nested Variational Autoencoder for Topic Modeling on Microtexts with Word Vectors

TL;DR

This paper introduces a nested variational autoencoder that leverages word embeddings and neural networks to improve topic modeling on microtexts, achieving better accuracy and faster runtime than traditional models.

Contribution

The paper presents a novel nested variational autoencoder model that incorporates word vectors for enhanced microtext topic modeling with scalable, efficient inference.

Findings

Improved topic coherence on microtexts.

Faster inference compared to traditional LDA.

Effective use of word embeddings in neural variational models.

Abstract

Most of the information on the Internet is represented in the form of microtexts, which are short text snippets such as news headlines or tweets. These sources of information are abundant, and mining these data could uncover meaningful insights. Topic modeling is one of the popular methods to extract knowledge from a collection of documents; however, conventional topic models such as latent Dirichlet allocation (LDA) are unable to perform well on short documents, mostly due to the scarcity of word co-occurrence statistics embedded in the data. The objective of our research is to create a topic model that can achieve great performances on microtexts while requiring a small runtime for scalability to large datasets. To solve the lack of information of microtexts, we allow our method to take advantage of word embeddings for additional knowledge of relationships between words. For speed and scalability, we apply autoencoding variational Bayes, an algorithm that can perform efficient black-box inference in probabilistic models. The result of our work is a novel topic model called the nested variational autoencoder, which is a distribution that takes into account word vectors and is parameterized by a neural network architecture. For optimization, the model is trained to approximate the posterior distribution of the original LDA model. Experiments show the improvements of our model on microtexts as well as its runtime advantage.