A Unified Theory of Representation Learning: How Hidden Relationships Power Algorithms that can Learn without Labels

How does the human mind make sense of raw information without being taught how to see or hear? This thesis presents a unifying theory that describes how algorithms can learn and discover structure in complex systems, like natural images, audio, language, and video - without human input. This class of algorithms has the possibility to extend our own understanding of the world by helping us to see previously unseen patterns in nature and science. At the core of this thesis’ unified theory is the notion that relationships between deep network representations hold the key discover the structure of the world without human input. This work will begin with a few examples of this principle in action; discovering hidden connections that span cultures and millennia in the visual arts, discovering visual objects in large image corpora, classifying every pixel of our visual world, and rediscovering the meaning of words from raw audio, all without human labels. In the latter half of this thesis, we will present two unifying mathematical theories of unsupervised learning. The first will explain why relationships between deep features can rediscover the semantic structure of the natural world by connecting model explainability, cooperative game theory, and deep feature relationships. The second mathematical theory will show that relationships between representations can be used to unify over 20 common machine learning algorithms spanning 100 years of progress in the field of machine learning. In particular, we introduce a single equation that unifies classification, regression, large language modeling, dimensionality reduction, clustering, contrastive learning, and spectral methods. This thesis uses this unified equation as the basis for a “periodic table of representation learning” that predicts the existence of new types of algorithms. We show that one of these predicted algorithms is a state-of-the-art unsupervised image classification technique. Finally, this work will summarize the key findings and share ongoing and future directions.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2025

Author dc:creator

• Hamilton, Mark T.

Advisor dc:contributor.advisor

• Freeman, William T.

Statement dc:rights

• In Copyright - Educational Use Permitted
• Copyright retained by author(s)

Licence dc:rights.uri

• https://rightsstatements.org/page/InC-EDU/1.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/164064

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/164064