Harvard STAT 110: Introduction to Probability
Stat 110 is Joe Blitzstein's celebrated probability course — counting, conditional probability, random variables, distributions, expectation, and Markov chains — known for its storytelling style and brutal-but-beautiful problems. Its free lecture videos have made it a global staple for self-learners and quant-interview preppers.
Fennie is independent and not affiliated with Harvard University. This is an unofficial study guide.
Build my STAT 110 study planWhat makes it hard
The lectures feel intuitive; the problems do not. Stat 110 psets demand creative problem-solving — choosing the right story, symmetry, or conditioning argument — and students who can follow every lecture still get stuck for hours on psets. Conditional probability and expectation tricks are the make-or-break skills.
What you'll cover
- • Counting and combinatorics
- • Conditional probability and Bayes' rule
- • Discrete and continuous random variables
- • Expectation, variance, and covariance
- • Joint distributions
- • Law of large numbers and CLT
- • Markov chains
The STAT 110 study guide
How to study for Harvard STAT 110, step by step.
- 1
Watch the lecture, then attempt problems immediately
Stat 110's lectures feel intuitive and the problems do not — that gap is the course. Whether you're enrolled or using the free online lectures, never let a lecture pass without attempting related problems the same day.
- 2
Work the strategic practice problems by theme
The course's strategic practice sets group problems by technique — conditioning, symmetry, indicator variables. Working them theme by theme builds the pattern recognition the psets demand.
- 3
Learn every distribution as a story
Blitzstein teaches distributions through the scenarios that generate them, and that's how exam problems are recognized. For each named distribution, know its story, support, expectation, and variance cold.
- 4
Struggle honestly before checking solutions
For self-learners using the textbook's solved problems: give each one a real attempt — hours, not minutes — before reading the solution. The struggle is where the problem-solving instinct gets built.
- 5
Space the practice with Fennie
Upload the Stat 110 syllabus or your self-study plan and Fennie schedules spaced problem practice paced to your timeline, with flashcards for the named distributions and their stories generated from the actual course material. Free to start.
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How Fennie helps with STAT 110
Fennie's Daily Plans schedule Stat 110 around spaced problem practice — the only known way to build the problem-solving instincts this course demands, whether you're enrolled or self-studying from the public lectures. Chat through why a conditioning argument works, and drill the named distributions and their stories with auto-generated flashcards.
FAQ
Is Stat 110 hard?
Yes — the gap between understanding lectures and solving psets is famously large. Plan for serious weekly problem time; the difficulty is creativity, not computation.
Can I self-study Stat 110 online?
Yes — the full lectures are free online and the course textbook (Blitzstein & Hwang) with practice problems is widely available. It's one of the most-recommended probability resources for data science and quant prep.
What math do I need for Stat 110?
Solid single-variable calculus and comfort with summations; multivariable helps for joint distributions. The real prerequisite is willingness to struggle productively with problems.
Pass STAT 110 with a plan, not a cram
Upload your STAT 110 materials and Fennie generates a Daily Plan paced to your deadline — plus chat, flashcards, and quizzes built from the actual course content.
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