Topic Models and Dimensionality Reduction

07 Dec 2017 . category: Notes . Comments

Topic flow chart (SVG)

Over the past few weeks, I spent some time building this slide deck1 as a comprehensive overview of the subject of topic models in NLP. It has been assembled from many other online resources, which I took care to cite throughout.


My motivations were many. I wanted to push myself to provide more visual content on this blog, and an original slide deck seemed like a good stepping stone towards that.

I also wanted to learn more about unsupervised learning techniques (having spent most of my recent time in the supervised domain), in hopes of ultimately building a prototype that could annotate notes to improve product search at work2.

Further, I wanted to brush up on my statistical fundamentals, as dimensionality reduction is a technique that seems to keep popping up everywhere in machine learning.

The fact that there’s a robust, popular Python library specifically for topic modeling in gensim proves (to me, at least) how interesting and practical topic modeling is. I hope you agree!

Exploratory Jupyter notebook for the slide deck: http://nbviewer.jupyter.org/github/iconix/nlp-sandbox/blob/master/topic_models.ipynb

Footnotes

  1. PowerPoint today, HTML5 next. I was not aware of how low res PowerPoint Online renders slide decks… ↩

  2. The prototype will have to wait though, as unfortunately, business priorities on the team have shifted enough to put the ML incubation team on pause for several months. ↩


Me

Nadja does not particularly enjoy writing about herself.