18.905: Algebraic Topology I

Table of contents

  1. Course Info
  2. Realistic Prerequisites
  3. Subject Matter
  4. Course Staff
  5. Lectures
  6. Problem Sets
  7. Exams
  8. Resources
  9. Grading

Course Info

Class Size 37
Hours/Week 10.3 (15 responses)
Instructors Jeremy Hahn
Overall Rating 6.4/7.0

Realistic Prerequisites

  • 18.701 is a hard prerequisite.
  • 18.901 is a soft prerequisite but helpful.
  • Familiarity with some concepts from 18.702 such as commutative rings, modules, and manifolds is very helpful.

Subject Matter

  • The class was very theoretical.
  • Students mentioned that there are many interesting applications to algebraic topology and this class covers the bases well and is useful for those hoping to explore the field further.

Course Staff

  • Professor Hahn was described as very approachable and engaging.


  • Lectures were described as somewhat slow and easy to follow.
  • Lectures focused on examples and told an interesting story.

Problem Sets

  • Problem sets were long, though were bi-weekly.
  • Problems were generally described as fun and challenging. They helped solidify an understanding of the material.


  • There were no exams besides the final.


  • Lecture notes by Prof. Haynes Miller were most useful.
  • Allen Hatcher’s Algebraic Topology was used, but did not follow the class material as closely.


  • Students felt that grading was fair and lenient.