Classification
Predicting categories (spam/not-spam, disease/healthy) is the most common ML task in the real world.
Learn it
Learn logistic regression and decision trees for classification, how they output class probabilities, and how to read a confusion matrix.
By the end you’ll be able to
- Train a classifier
- Read a confusion matrix
Free resources
- StatQuest — Logistic Regression (video)(opens in a new tab)Start here
Clear intro to the S-curve classifier
Free~9 min - StatQuest — Decision and Classification Trees (video)(opens in a new tab)
How trees split and classify
Free~18 min - Kaggle Learn — Intro to Machine Learning(opens in a new tab)
Hands-on decision trees and random forests
Free3 hr - Google — Logistic Regression module(opens in a new tab)
Sigmoid, log loss, thresholds
Free35 min
Practice
Train a classifier on the Titanic dataset to predict survival, then read its confusion matrix.
Build it — your output
A trained classifier for a real yes/no question, with accuracy and a confusion matrix explained in words.
Prove it — check yourself
You’re ready to move on when you can honestly say yes to each:
- Can you train a classifier?
- Can you read a confusion matrix?
- Do you understand class probabilities?
Do it with AI
Use a free AI tool as your tutor and pair-programmer. Copy a prompt below into Claude, ChatGPT, or Gemini (for building, try Cursor or Copilot).
The habit: Try it yourself first — a little struggle is where the learning actually happens. Then ask for a hint before the answer — never copy blindly.
- Understand itClaude / ChatGPT / Gemini
I'm a beginner learning "Classification". Explain it in simple terms with a real-world analogy, then ask me ONE question to check my understanding — don't reveal the answer.
- PracticeClaude / ChatGPT / Gemini
Give me 3 short practice problems on "Classification" (my goal: train a classifier), from easy to hard. Don't include the solutions yet — I'll try them first, then ask you to check.
- Get unstuckClaude / ChatGPT / Gemini
I'm stuck on this exercise about "Classification": [paste your attempt here]. Give me ONE small hint to move forward — do NOT give me the full solution.
- Build & reviewCursor / Copilot
Here is my work for a "Classification" task: [paste your code or answer]. Review it: point out what's wrong and WHY, and suggest improvements — but let me make the fixes myself.
- Prove itClaude / ChatGPT / Gemini
Quiz me on "Classification". Ask me 5 questions one at a time, wait for my answer each time, then tell me if I'm right and briefly why.