In my previous article, I looked at defining your success goals and what to measure when running multivariate tests. Let's now look at your site factors and learn how to select the right ones to test.
By now, your marketing goals are clearly defined and you're ready to run a multivariate test to optimize your site's marketing effectiveness... but which elements, or factors, should you test?
What Is a Site Factor?
First, let's define what a factor is. A site factor is a distinct, single element that you can control for testing purposes, and each version of a factor is called a variation. Through testing, you'll discover that some factors are influential and have a causal relationship with user behavior—modifying them changes how users behave, ideally motivating them to reach your marketing goalposts (e.g., checkout, registration, or simply spending more time on your site.) Others factors are not influential, and have little to no impact on what users do.
One of the keys to multivariate testing is in selecting factors to test, and defining them so that they may be accurately analyzed.
Many unique factors exist on every site, and they vary in scope from narrow to broad. For example, a factor could be an element on a single page, such as a headline, image, or paragraph of copy. Or, it might span pages or exist across a particular section, such as a navigation component, product category promotion, or a call-to-action. As well, a site factor could span your entire site, such as a text style (CSS), or grid layout spacing (e.g., how much space is allocated for main content vs. advertising vs. widget areas, etc.).
Choosing Site Factors
If multivariate testing gives us the ability to simply throw everything at the wall to see what sticks, what's the big deal with choosing specific factors to focus on? Why not just test everything and anything? While identifying factors isn't that hard, coming up with a broad range of variations takes time and effort. For example, think of the creative resources required for coming up with five variations for each of 20 different site factors, which could include everything from the page title to the copyright in the footer. While it's technically possible to test it all factors and their variations at once, it's much easier to be organized and test fewer factors that have a higher likelihood of actually making a difference.