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CS109: Probability for Computer Scientists

Summer 2026

Monday, Tuesday, Wednesday, Thursday 10:30am - 11:45am in-person in CoDa B80

Teaching Team

Instructor:
Chris Gregg

OH: Fri 9-11am
CoDa E128

Head TA:

cs109 @ cs.stanford.edu

This Week in CS109

Date	Lecture	Outside Class
Mon, June 22nd	Welcome / Foundations	Lecture 1 LLM Learning Guide
Tue, June 23rd	Conditioning and Bayes	Lecture 2 LLM Learning Guide
Wed, June 24th	Independence	Lecture 3 LLM Learning Guide
Tue, June 25th	Counting	Lecture 4 LLM Learning Guide

Welcome

Welcome to CS109! We are looking forward to an uplifting and exciting quarter. Class starts Monday, June 22nd at 10:30am PT in CoDa B80. See you there 🌱.

Getting Started in CS109

The Syllabus page has details on course logistics.
The Honor Code handout describes how the Honor Code applies in the context of the work you will do in CS109.
The Schedule page has a list of all topics that we will cover in CS109, the lecture schedule, and the problem set dates and deadlines.
The Office Hours page has contact information for the teaching team. Office Hours will be listed on this calendar and start on Wednesday, April 1st.
Section enrollment details will be released on the first day of class; you do not enroll in section via Axess.

RESOURCES

Discussion
Course Reader
Syllabus
Schedule
Office Hours

Key Dates

Midterm 1: July 13th, in-class
Midterm 2: Aug 4th, in-class
Final: Aug 15th, 8:30am
Last lecture: Aug 12th

Course Values

Everyone is welcome. Intellectual joy. Be kind. Be humane. Social connection. Learn by doing. Thrill of building. Adapt to new contexts.

CS109: Probability for Comp. Science

Summer 2026, MWF 10:30am - 11:45am, CoDa B80