Probably Random - Statistics for people who use numbers, not degrees
Statistics for people who use numbers, not degrees
What Is P-Hacking
P-hacking is running several analyses on the same data until one of them comes out statistically significant, usually p < .05, and then reporting that one...
Desmond Achebe • 6 min readWhy a Bigger Sample Shrinks Your P-Value
Why does the same small lift look like noise in a small test and a sure thing in a big one? Because a p-value depends on two things, not one. It reflects...
Meera Krishnan • 5 min readWhat 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 readP-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 readWhy 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 readHow 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 readRegression 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 readElection 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