Probably Random - Statistics for people who use numbers, not degrees

Statistics for people who use numbers, not degrees

What Counts as a Good P-Value

There is no single good p-value. What counts as "good enough" depends on your field and on what a false alarm would cost you. The conventions run from 0.10...

Meera Krishnan • 6 min read
Oct 7, 2026

P-Value vs Confidence Interval

If you have both a p-value and a confidence interval for the same result, read the interval first. The two come from the same arithmetic, so a 95%...

Sofia Bianchi • 7 min read
Oct 4, 2026

Why 0.05 Is the Standard P-Value Cutoff

Why is the p-value cutoff 0.05? Ronald Fisher, a British statistician, called it convenient in a 1925 textbook, and nearly everyone followed him. It is a...

Sofia Bianchi • 5 min read
Oct 1, 2026

How to Calculate a P-Value by Hand

When you finish, you will have a two-tailed p-value for a one-sample t-test, built from four numbers: the sample mean, the sample standard deviation, the...

Meera Krishnan • 5 min read
Sep 28, 2026

Regression to the Mean, Explained With Real Numbers

Why does the sales rep who had a record month usually have an ordinary one right after? Most of the time the cause is regression to the mean: an unusually...

Meera Krishnan • 5 min read
Sep 25, 2026

Election Win Probability Charts Aren't Vote Shares

When a forecast says Democrats have an 85 percent chance of winning the House, that is not a prediction that they will win 85 percent of anything. It is a...

Meera Krishnan • 6 min read
Sep 22, 2026

Why 2026 Midterm Forecasts Disagree So Much About Who Wins the House

Three forecasts of the same midterm elections are live this month and they look irreconcilable. A Cornell University model presented on September 3, 2026...

Meera Krishnan • 7 min read
Sep 18, 2026

How Publication Bias Kept a Fabricated Procrastination Study Famous for 24 Years

Publication bias is the tendency for a study to get published because of how its results turned out rather than how well it was done. Big, clean, surprising...

Meera Krishnan • 6 min read
Sep 18, 2026

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