Phase 2 · Math, when you need it · Probability & statistics
Probability basics
Events, outcomes and the rules for combining them.
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Why it matters
A language model doesn't output a word; it outputs a probability for every possible next word. Classifiers output probabilities, evals estimate them, and A/B tests are built on them. Marketers already reason in probabilities (open rates, conversion rates, churn), usually without the rules that keep the reasoning straight. A few rules, plus the habit of checking them by simulation, cover most of what you'll need.
What you'll be able to do
- Describe outcomes, events and probabilities between 0 and 1
- Use the complement, addition and independence rules
- Compute 'at least one' probabilities
- Check a probability formula by simulating it with random numbers
Before this lesson
Next in this phase: Conditional probability and Bayes