AB Testing in a Single Page App

For the last year I’ve been working on building a new web application using backbone.js to drive all our ui. For someone who has been doing web development for 15 years the transition to from the server side mindset took a bit of adjustment, but overall I’ve been pleased with the result.

One area that continues to cause us issues as we integrate in other services is the assumptions that are made about basic things like page onload. In a traditional web application assuming each page will generate an onload is a pretty safe one. However for an Single Page App (SPA), it’s not and getting around that assumption can be a challenge.

Our most recent run in with this was in integrating Google’s new Content Experiments into our site to do some AB testing. In a “normal” implementation content experiments will rewrite the URL to direct the user to the variant it wants. For some cases this did not cause an issue in our app. If the user refreshed however things got messy depending on where they were in the application.

At first I didn’t think there were any other options, but eventually found some interesting posts at Conversion Works blog (http://www.conversionworks.co.uk/blog/2012/06/18/google-content-experiments-testing-templates-and-sitewide-content/) Based on their experience we modified the GA CE JavaScript to set the combination variable and changed our Backbone view to behave differently based on which one is set. From our initial testing seems to work well. In a later post they note needing to add a query parameter if you want visits to be shown correctly in the content experiments UI.