On 21 January 2015 Optimizely — one of the most widely used A/B testing platforms in the world — switched…
In the Israeli Air Force, Daniel Kahneman recounts, the flight instructors were sure of one thing: praising a cadet after…
Over the previous articles we have looked at how hypothesis testing works and how the two-sample t-test lets us compare…
Principal Component Analysis (PCA) is a widely used statistical technique for reducing the complexity of large datasets. It aims to…
Anyone who looks at a website's data does it constantly, often without noticing: they spot that two things seem to…
We closed the article on the A/B test significance calculator with a promise. We said that the p-value answers a…
Our A/B test has run its course: variant B shows a higher conversion rate than variant A. The temptation to…
There is a question that comes back, reliably, every time I publish an article along this path: "so, which book…
It's the last day of the month. We're putting together the SEO report for our main client. We open Google…
In this article: How to Choose Who to Measure: Types of Sampling Sample Size: The Math Behind the Estimation Let's…