Keyword-based Topic Modeling and Keyword Selection
This work addresses the challenge of adaptive keyword selection for document collection in dynamic environments like social media, representing an incremental improvement over existing methods.
The paper tackles the problem of dynamically selecting keywords to collect future documents like tweets, where topics change over time, by developing a keyword-based topic model that outperforms a baseline model by 67% in viral tweet predictions.
Certain type of documents such as tweets are collected by specifying a set of keywords. As topics of interest change with time it is beneficial to adjust keywords dynamically. The challenge is that these need to be specified ahead of knowing the forthcoming documents and the underlying topics. The future topics should mimic past topics of interest yet there should be some novelty in them. We develop a keyword-based topic model that dynamically selects a subset of keywords to be used to collect future documents. The generative process first selects keywords and then the underlying documents based on the specified keywords. The model is trained by using a variational lower bound and stochastic gradient optimization. The inference consists of finding a subset of keywords where given a subset the model predicts the underlying topic-word matrix for the unknown forthcoming documents. We compare the keyword topic model against a benchmark model using viral predictions of tweets combined with a topic model. The keyword-based topic model outperforms this sophisticated baseline model by 67%.