Quantitative intuition for people who work with data.
Real-world case studies, interactive simulations, and the intuition behind every formula — for analysts, engineers, and anyone who reasons with numbers.
Case studies, essays, and guides — how the math gets used, misused, and where intuition catches what the dashboard misses.
When Dashboard Averages Hide a Churn Cliff
The dashboard says average 30-day retention is 42%. Leadership is reassured. The number describes a user who doesn't exist — half the cohort churned in week one, and a small group of power users carries the rest. Here is what the average is hiding.
Why Your A/B Test Peeks Lie
Stopping a test the moment p drops below 0.05 doesn't make you fast — it inflates your false positive rate from 5% to over 20%. Here is what peeking actually does to your numbers, and what to do instead.
Intuition-first explainers — the surprising question, the visual, then the math.
Standard Deviation and Variance
Why spread matters as much as the average, and how to measure it.
Regression Intuition
What a regression line actually is, why it's the best line, and what R² is really telling you.
The Normal Distribution
Why so many things in nature cluster around a middle value — and how to read the bell curve.
Correlation vs. Causation
Why two things moving together doesn't mean one causes the other — and how to tell the difference.
Bayes' Theorem
How a positive test result can still be mostly wrong — and how to update beliefs correctly when evidence arrives.
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Curated reading routes through the concepts and field notes, ordered so each builds on the one before it.