CSE 541Autumn 2026

University of Washington · Paul G. Allen School

CSE 541: Interactive Learning

Bandits, online learning, and experimental design: algorithms that decide what data to collect next.

Lectures
Mon & Wed, 10:00–11:20 AM
ECE 037
Instructor
Kevin Jamieson
Office hours: Tue 3:00–4:00 PM, CSE2 340
Teaching assistants
Contact

Announcements

  • Sep 30Welcome! The first lecture is Wednesday, September 30, in ECE 037. Please try the HW0 self-test during week 1.

About the course

The traditional approach to machine learning uses a training set of labeled examples to learn a prediction rule that will predict the labels of future examples. Collecting such training sets can be expensive and time-consuming. This course explores methods that use already-collected data to guide future measurements, in a closed loop, to best serve the task at hand. We focus on two paradigms:

  • Pure exploration: algorithms that identify or learn a good-enough model using as few measurements as possible (e.g., classification, drug discovery, science).
  • Regret minimization: algorithms that balance taking measurements to learn a model against exploiting that model to obtain high-reward outcomes (e.g., content recommendation, medical treatment design, ad serving).

The literature on interactive (machine) learning has exploded in recent years and can be overwhelming. This course classifies interactive learning problems by characteristics such as the hypothesis space, the available actions, the measurement model, and the available side information. We focus on general algorithmic strategies and common proof techniques. By the end of the course, you will be in a position to begin research in this field, or to lead an interactive-learning software implementation in industry.

Topics

Selected topics from

  • (Non-)stochastic online learning
  • (Non-)stochastic multi-armed bandits
  • (Non-)stochastic linear bandits and experimental design
  • (Non-)stochastic contextual bandits (model-free and model-based)

Prerequisites

The course refers often to introductory machine learning (e.g., CSE 446/546), but it is not a prerequisite. We assume fluency with linear algebra, probability and statistics, and calculus. The course is analysis-heavy, with a focus on methods that work well in practice.

Work through the HW0 self-test on your own (not turned in or graded). You should be able to do most of it in your head or with minimal computation.

Review materials

Class materials

Lecture slides (PDF) are posted on the schedule before each class. Bring them to lecture if you like to annotate. The course also draws on these texts and notes:

Grading and policies

Grading

Three homeworks (10% each) and two projects, one at the midterm and one at the end of the quarter (35% each).

Projects

There are two projects, one due at the midterm and one at the end of the quarter. For each, you pick a topic that extends a tool from the course and explain it to your classmates. Each project has two parts:

  • A 5-minute YouTube video (±30 seconds; it can be unlisted). Slides with a voiceover, a whiteboard talk, or an animated explainer are all fine. Production quality isn’t graded. Clarity and accuracy are, and at least one big idea should come across clearly. Please add captions; YouTube’s auto-captions, corrected where they’re wrong, are fine.
  • A 2–3 page writeup in LaTeX, submitted as a PDF on Gradescope. It introduces the problem, surveys the relevant papers, states results correctly, and identifies what is open.

Share both in an Ed post titled “[Your name]: [Project title]”. Projects are individual (one per person), and topics and the full rubric are in each project’s handout. The late policy does not apply to projects, so plan ahead.

AI policy

CSE 541 follows the Allen School “AI for Collaboration” policy. You may use AI tools on any course work, including homeworks and projects, unless a specific activity says otherwise. In return:

  • Supply the algorithm yourself. AI may turn an algorithm you have fully specified into code, but “implement UCB” is not allowed. See the example below.
  • Proofs are yours. On proof-based questions, use AI only minimally (clarifying concepts, brainstorming approaches, LaTeX formatting), never to write or fix the proof.
  • Attribute it. Add a short note to each graded submission naming the tool and how you used it.
  • Own it. You are responsible for checking AI output, and you should be able to explain and defend everything you submit.
  • Protect data. Don’t upload restricted course materials (solution keys, other students’ work) or personal information, and scope what coding agents can access.

Collaboration policy

With classmates

Homeworks must be done individually: each student hands in their own answers and writes their own code. It is fine to collaborate with classmates in figuring out answers and helping each other solve problems, but list the people you collaborated with on each homework. If you find yourself copying and pasting code, LaTeX, or anything else from another student, you have crossed the line.

With AI: you supply the algorithm, AI can help you type it

You may use AI to turn an algorithm you have fully specified into code: the update rules, what is sampled, what is observed, and what is computed. You may not ask AI to supply the algorithm itself. Naming the method and asking the AI to “implement it” hands over exactly the thinking the homework is meant to exercise.

Not acceptable
“Implement UCB.”

The AI decides what the algorithm is. You haven’t shown that you know it.

Acceptable
“We’re going to implement a multi-armed bandit algorithm. At each time in a loop, we’re going to compute the UCB for each arm i as UCB(i)=μ^(i)+2log(t)N(i) where t is the current iteration number, μ^(i) is the ith empirical mean and N(i) is the number of times the ith arm has been pulled. We will pull argmaxi UCB(i), observe Xi,t = μ(i) + η(t) where μ(i) is the true ith mean that will be defined later and η(t) ~ N(0, 1). This loop will run for T rounds to be specified later when we talk about how to nicely plot relevant statistics.”

You specified every step. The AI is just translating your algorithm into Python.

For code, a rule of thumb: if someone who had never heard of the algorithm could write the code from your prompt alone, you’re on the right side of the line. Routine code, such as making well-formatted plots, loading data, or debugging your own implementation, is always fine. Whatever you use AI for, say so in your submission (see the AI policy).

With AI on proofs: keep it minimal

For proof-based questions, use AI minimally: to clarify a definition or concept, to brainstorm possible approaches, or to help with LaTeX formatting. Do not ask AI to write, complete, or fix your proof. The argument and its details should be yours.

The homework problems have been chosen for their pedagogical value and may be similar or identical to those given in past offerings of this course at UW or similar courses elsewhere. Using pre-existing solutions from these sources, the web, or textbooks violates the academic integrity expected of you and is strictly prohibited. This includes asking an AI tool to find or reproduce such solutions.

Submitting homework

Submit each homework as a single, typeset PDF to Gradescope (no photos or scans). You are enrolled in Gradescope automatically; email us if you don’t see the course. Code for a programming problem goes at the end of that problem, after any requested figures. LaTeX is strongly recommended, and there are convenient packages for listing Python code.

LaTeX resources: Overleaf (online editor) · Learn LaTeX in 30 minutes · Math symbols · Detexify (draw a symbol to find it) · Install LaTeX locally · Gradescope help

Late policy

Need an extra 24 hours on a homework? No problem, and no permission needed. If you need several days for personal reasons, email the instructor before the due date; I will try to be accommodating, but please don’t abuse this. Work turned in more than 24 hours late without prior permission is late and may receive zero credit. Projects are excluded: they have firm deadlines.

Regrades

Submit regrade requests through Gradescope within 7 days (24×7 hours) of grades being released, with a written explanation. A regrade may cover the entire assignment, so your grade may go up or down. Office hours are for course content, not grade questions.

Discussion and communication

Ed is our discussion board and your first stop for questions (registered students receive an invite; otherwise email the instructor). We will not use the Canvas discussion board. For private matters, email cse541-staff@cs.washington.edu or the instructor directly. You can also send anonymous course feedback, though I can’t reply to it personally.

Access and accommodations

Your experience in this class is important to me. It is the policy and practice of the University of Washington to create inclusive and accessible learning environments consistent with federal and state law.

  • Already have accommodations with DRS? Activate them for CSE 541 through myDRS early in the quarter so we can talk about how they will work in this course (for example, extended time or alternative formats).
  • Not yet registered? If you have a temporary health condition or permanent disability that requires accommodations (including, but not limited to, mental health, attention-related, learning, vision, hearing, physical or health impacts), contact Disability Resources for Students (DRS) directly to set up an Access Plan. DRS facilitates the interactive process that establishes reasonable accommodations.

You don’t need to share your diagnosis with the course staff. Reach out to the instructor or cse541-staff@cs.washington.edu anytime with questions about access in this course.

Assignments

Homeworks and project handouts are posted here when released. Tentative due dates are on the schedule. Everything is due at 11:59 PM Pacific.

Homework 0: prerequisite self-test
Not collected. Complete it in week 1.

Schedule

Lectures are added here as we go, each with its slides posted before class. Due dates are tentative. [Jamieson] = the course notes.

Lecture schedule and due dates
#DateTopic and readingSlides
1Wed Sep 30
Welcome and logistics; generalization bounds for classification (realizable and agnostic); online learning: the Halving algorithm, regret, exponential weights
[Jamieson] Ch. 2–3. Review prerequisites; try the HW0 self-test
Slides for lecture 1
2Mon Oct 5
Squared loss: fast rates via Bernstein, mixability and improper learning; universal portfolio optimization; online convex optimization and online gradient descent
[Jamieson] §2.3, Ch. 4–6
Slides for lecture 2
Tue Oct 20Homework 1 due, 11:59 PM
Sun Nov 8Midterm project (video + writeup) due, 11:59 PM
Wed Nov 11Veterans Day: no class
Sun Nov 22Homework 2 due, 11:59 PM
Sun Dec 13Homework 3 due, 11:59 PM
Tue Dec 15Final project (video + writeup) due, 11:59 PM