statistics

Keyword Clustering: grouping thousands of queries with K-means and hierarchical clustering

It happens with every reasonably serious project: you export the keyword list from Search Console or a tool, and you…

1 month ago

Expected vs Actual CTR: finding the pages that earn fewer clicks than their position deserves

Anyone who spends their days inside Search Console knows that little nagging feeling: a page sits steadily in third position,…

1 month ago

Naive Bayes: classifying search intent with Bayes’ theorem

In the article on the multi-armed bandit we used Bayes to decide between variants: shifting traffic toward the one converting…

1 month ago

Multi-armed bandit: optimising the variants while the test is still running

In the article on Bayesian A/B testing we compared two variants at a fixed sample size: we collect the data…

1 month ago

Bayesian A/B Testing: not just “whether” B beats A, but “by how much”

In the article on classic A/B testing we saw how to compare two variants with the two-proportion test: we compute…

2 months ago

Bayesian Conversion Rate Estimation: how much can we trust limited data

In the article on the foundations of Bayesian statistics, we saw how Bayesian updating works through simulation: generate samples from…

2 months ago

The peeking problem: why sneaking a look at an A/B test inflates false positives

On 21 January 2015 Optimizely — one of the most widely used A/B testing platforms in the world — switched…

2 months ago

Regression to the Mean: the SEO Fix That Worked… by Accident

In the Israeli Air Force, Daniel Kahneman recounts, the flight instructors were sure of one thing: praising a cadet after…

2 months ago

A/B Testing: How to Run Statistically Valid Experiments (and the Mistakes to Avoid)

In this article: What an A/B test is Setting up an A/B test correctly Worked example: conversion rate of two…

2 months ago

PCA (Principal Component Analysis): reduce SEO data complexity without losing insights

In this article: What PCA is The mathematical foundations Practical applications PCA in web marketing Implementing PCA in R Verification…

2 months ago