Become great at statistics for A/B testing

Avoid costly testing mistakes stemming from misuse and misunderstanding of statistic

If you’re not fluent in A/B testing statistics, you won’t be able to tell whether your tests suck.

Online course

By Georgi Georgiev,

Owner @ Web Focus

Course length: 3h 30min

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English subtitles Certificate included

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A lot of your “winning” tests are probably not winners at all. Learn to call bullshit when needed, and be the person who advocates proper scientific approach in your team.

In 10 sessions, you’ll learn

  • How to run A/B tests with a sound statistical design in a variety of scenarios – multiple test variants, multiple outcomes, non-binomial data, and others.
  • How to align the statistical design with the questions at hand to get business insights while avoiding common mistakes.
  • The logic behind statistical hypothesis testing and concepts like statistical significance, confidence intervals, statistical power, and others.

Course overview

Understand the complexities involved in planning and evaluating A/B tests

Avoid costly testing mistakes stemming from misuse and misunderstanding of statistics, and improve the ROI of all your A/B testing efforts, with Georgi Georgiev’s guidance.

Skills you will master

A/B testingA/B testing statisticsSample sizeSignificance and confidence intervalsStatistical powerStatistics

Anyone interested in genuinely understanding the math behind CRO and A/B testing absolutely has to use CXL. My whole team has a great time discussing the material and aligning our views on processes we use, and to come up with ideas to implement in the future.

Radvilas Š.

This course is right for you if…

  • You can’t define statistical significance correctly without looking it up on Google.
  • Your A/B tests produce a lot of “winners,” but your clients aren’t seeing improvements.
  • You’re planning and analyzing A/B tests, but you don’t understand the statistical underpinnings of the testing process.
  • You’re not confident in the outcomes of your tests and are unsure how much trust to put in them
  • You have an in-house statistical tool you want to improve, or you use a third-party A/B testing software you want to understand better

This course is probably not for you if…

  • You are just starting with CRO and have little to no practical experience with A/B testing.
  • You don’t employ A/B tests as a primary method to evaluate CRO work.
  • You are a professional statistician or experimental design specialist.

Skills you should have before taking this course:

  • Some experience in conversion rate optimization.
  • Basic understanding of how A/B testing works.
  • Some experience with an A/B testing software.

Georgi Georgiev

Owner @ Web Focus

Georgi is an expert internet marketer and statistician working passionately in the areas of SEO, SEM and Web Analytics since 2004. He is the founder of Analytics-Toolkit.com and owner of an online marketing agency & consulting company: Web Focus LLC and also a Google Certified Trainer in AdWords & Analytics.

His special interest lies in data-driven approaches to testing and optimization in e-commerce and internet advertising and Georgi is also the author of three papers, multiple articles on A/B testing for conversion rate optimization, as well as the book “Statistical Methods in Online A/B Testing”.

In just 10 sessions, you’ll be able to

  • Plan A/B tests by taking into account relevant error probabilities
  • Correctly interpret A/B testing statistics like p-values and confidence intervals.
  • Navigate the complexities of MVT, segmentation, multiple KPIs, and concurrent tests.
  • Efficiently communicate A/B test statistics.

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  • Learn how to calculate statistical significance

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Your full course curriculum

Statistics for A/B testing

1 Basics of Causal Inference

Lesson Objectives: Understand the difficulties involved in making sense of data in a noisy worldLearn how experiments help us deal with some of those difficultiesEstablish the role of statistics in making business decisionsTranslate business questions

2 Statistical Significance & Other Estimates

Lesson Objectives: Understand the need for the p-value and what it meansLearn how to calculate the p-value for absolute difference in proportionsIntroduce confidence intervals as an alternative presentation of the discrepancy between observations and a

3 Statistical Power & Sample Size Calculations

Lesson Objectives: Understand type II errors, the concept of statistical power of a test, and how to account for them in planning an A/B testLearn how to determine the required sample size for a simple A/B testUnderstand the relationship between power,

4 Multivariate Tests

Lesson Objectives: Understand what challenges are posed by A/B/n designs & the different tools for addressing themUnderstand the implications of increasing the number of variants testedExplore the trade-off between testing many variants and testing

5 Running Concurrent A/B Tests

Lesson Objectives: Explore the complications introduced by running concurrent testsUnderstand why commonly-proposed approaches do not get the job doneLearn how and if to engage in concurrent testing Lesson 5 slide deck

6 Tests With Multiple Outcomes

Lesson Objectives: Understand the difference between primary and secondary outcomesLearn how to recognize situations which require FWER control and which do notDesign tests with multiple primary and secondary outcomes Lesson 6 slide deck

7 Non-binomial data

Lesson Objectives: Understand the three types of metrics in A/B testingCut through common misconceptions about statistics based on non-binomial dataCalculate statistical estimates for non-binomial data Lesson 7 slide deck

8 Statistics for Percentage Change

Lesson Objectives: Explore the difference between absolute and relative or percentage differenceDefine a proper statistical model for percent changeCalculate statistical estimates for working with percent change outcomes Lesson 8 slide deck

9 Asking the Right Questions

Lesson Objectives: Recognize when a one-sided test is appropriateUnderstand the need for correspondence between substantive(business) and statistical hypothesisLearn how to translate different business questions to appropriate statistical hypotheses Le

10 Communicating Statistical Results

Lesson Objectives: Learn how to prepare stakeholders for using statistical insightsExplore best practices for presenting statistical insights through graphs, stories, tables, etc. Lesson 10 slide deck

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Learn A/B Testing Statistics: FAQ

Who is this course for?

This course is right for you if…

  • You can’t define statistical significance correctly without looking it up on Google.
  • Your A/B tests produce a lot of “winners,” but your clients aren’t seeing improvements.
  • You’re planning and analyzing A/B tests, but you don’t understand the statistical underpinnings of the testing process.
  • You’re not confident in the outcomes of your tests and are unsure how much trust to put in them
  • You have an in-house statistical tool you want to improve, or you use a third-party A/B testing software you want to understand better

Some careers that will especially benefit from this course are CRO specialist, growth marketer, digital marketing manager, product manager, UX designer, data scientist, software engineer, web developer, or business analyst.

What will you learn?

After taking this course, you will:

  • How to run A/B tests with a sound statistical design in a variety of scenarios – multiple test variants, multiple outcomes, non-binomial data, and others.
  • How to align the statistical design with the questions at hand to get business insights while avoiding common mistakes.
  • The logic behind statistical hypothesis testing and concepts like statistical significance, confidence intervals, statistical power, and others.

What does the course include?

Our A/B Testing Statistics training includes 11 lessons, 10 downloadable resources, 3h 30min of video material, several assignments, and a final exam.

Are subtitles available for the lessons?

Lessons have English subtitles and transcriptions available.

Will I receive a certificate of completion?

After taking this course, you will receive the A/B Testing Statistics Certification from CXL, with credentials that you can add to your LinkedIn profile.

What is the refund policy?

All plans come with a 7-day refund period .

How long will it take for me to finish it?

This is entirely up to you – it’s how many study hours per week you can put in. This course is 3h 30min long.