Week 13 β Unsupervised (11/14β18)#

In this week, we are going to talk more about unsupervised learning β learning without labels. We are not going to have time to investigate these techniques very deeply, but I want you to know about them, and you are experimenting with them in Assignment 6.

This weekβs content is lighter, since we just had a large assignment and a midterm, and another assignment is due on Sunday.

π§ Content Overview#

Element Length

π₯Β No Supervision

2m51s

π₯Β Decomposing Matrices

17m22s

π₯Β Clustering

6m56s

π₯Β Vectors and Spaces

7m27s

π₯Β Information and Entropy

10m31s

This week has 0h45m of video and 0 words of assigned readings. This weekβs videos are available in a Panopto folder.

π₯ No Supervision#

In this video, we review the idea of supervised learning and contrast it with unsupervised learning.

π₯ Decomposing Matrices#

This video introduces the idea of matrix decomposition, which we can use to reduce the dimensionality of data points.

π Movie Decomposition#

The Movie Decomposition notebook demonstrates matrix decomposition with movie data.

π₯ Clustering#

This video introduces the concept of clustering, another useful unsupervised learning technique.

π Clustering Example#

The clustering example notebook shows how to use the KMeans class.

π₯ Vector Spaces#

This video talks about vector spaces and transforms.

π₯ Information and Entropy#

This video introduces the idea of entropy as a way to quantify information. Itβs something I want to make sure youβve seen at least once by the end of the class.

Resources#

Take the Week 13 quiz on Canvas.

π Practice: SVD on Paper Abstracts#

The Week 13 Exercise notebook demonstrates latent semantic analysis on paper abstracts and has an exercise to classify text into new or old papers.

It requires the chi-papers.csv file, which is derived from the HCI Bibliography. It is the abstracts from papers published at the CHI conference (the primary conference for human-computer interaction) over a period of nearly 40 years.

If you want to see how to create this file, see the Fetch CHI Papers example.