Recently I wrote a blog post that mentioned “Superiority” as a type of A/B test decision. In this post I want to talk about all five types of A/B test decision that I think are relevant. This is an adaptation and extension of a talk I gave last year at the Quant UX conference (it’s a great event, you should check it …

The "best practice", when evaluating the results of an online controlled experiment (A/B test), is to use classical statistical tests, proceeding with a change if (and only if) the result of the test includes a p value of less than 0.05. But, the American Statistical Association (ASA) said in a prominent 2016 …

A/B testing is a tool for supporting decision-making in business, and so in addition to getting the statistics right, it’s really important to communicate well with the non-statisticians who will have the final say on the go/no-go decision. Most A/B tests in practice are testing ratios, conversion rates of various …

Suppose you’re a data scientist at an e-commerce web site that sells shoes, responsible for supporting A/B tests. Many A/B tests are easy, and there are a number of companies that sell tools that make the easy cases as simple as clicking a few buttons and looking at pretty graphs. But A/B tests can get statistically …

For a project I’m working on at work, I’m building a predictive model that categorizes something (I can’t tell you what) into two bins. There is a default bin that 95% of the things belong to and a bin that the business cares a lot about, containing 5% of the things. Some readers may be familiar with the use of …

I recently attended the INFORMS Conference on Business Analytics and Operations Research, aka “INFORMS Analytics 2011”, conference in Chicago. This deserves a little bit of an explanation. INFORMS is the professional organization for Operations Research (OR) and Management Science (MS), which are terms describing …

Neil Saunders has an interesting (to me) blog post up this morning, with the title “Dumped on by data scientists.” He uses the use of “data scientist” in a Chronicle of Higher Ed article to rant a little bit about the term. For Neil, it’s redundant, as the act of doing science necessarily requires data; it’s insulting, …

The Meetup phenomenon, which is now substantial and longstanding enough to be more of a cultural change than a flash in the pan, continues to impress me. Even more so than tools like LinkedIn, Meetups have changed the nature of professional networking, making it more informal, diverse, and decentralized. Last night, …