Wednesday, January 29, 2014

A/B testing vs. Multivariate testing

The following articles give us a good overview of the differences between A/B testing and multivariate testing.

http://visualwebsiteoptimizer.com/split-testing-blog/difference-ab-testing-multivariate-testing/
http://searchengineland.com/landing-page-testing-choosing-between-ab-or-multivariate-approaches-27195

Snippets from the articles:

A/B testing consists of creating alternative pages for a specific page and showing each of them to a certain percentage of visitors. For example, if you create 4 different variations of a landing page, 20% of visitors to the website will see each version (4 variations + original). Cookies are used to maintain a consistent user experience—if a visitor sees one version, they will see it again and again when visiting the website as long as the cookies are not deleted.

Rather than testing different versions of web pages, as we do with A/B tests, Multivariate tests experiment with elements inside one specific page. Basically, we define elements inside a page (e.g. a picture, a text or a button) and provide different alternatives of each element. The testing tool will show each element combined with all other elements to visitors. The resulting combinations are derived from the number of elements multiplied by the number of element variations. Just as with A/B testing, however, each visitor sees only one particular combination of elements regardless of how many times they view a page. 

Hence A/B testing is best for testing radically different ideas for conversion rate optimization. Multivariate testing is more granular and is best for optimizing and refining an existing landing page or homepage without doing significant investment in redesign.