It’s a fact of life that when people hire a web designer, they don’t just want a website, they want a website that does something! There can be a world of difference between these two things. The "action" they need the website to take for them can be one of several common things: selling products for their business (an e-commerce site), generating sales leads, and/or providing free information in the hope that the visitor will make a purchase from the company at a later date.

Here we look at how to determine which aspects of your web design work is most effective to help the client’s website achieve its aims, by a process known as split testing.

What is Split Testing?

Split testing (also known as A/B testing), is software that splits the traffic between two or more variants of the same web page, measuring whether there is a difference in the effectiveness of that page in achieving the website’s goals. Every time a visitor takes the desired action on a website, such as making a purchase or submitting a form, it is called a conversion.

Web designers might check whether:

• A landing page with a graphic of a person encourages better conversion rates than one with a graphic of the product
• A different positioning of the shopping cart button encourages more people to click it
• A form with fewer elements, or different elements, encourages more people to finish filling it out.

Just about every aspect of a website can be split-tested.

For most websites, A/B split testing will be the optimum method of improving a website’s conversion rate over time.

Why Bother With Split Testing?

Split testing is what separates elite web designers from the rest because it provides them with the knowledge of which combination of website elements will produce the optimum results for the client and they can demand a higher rate as a result. Split testing can help:

• Get visitors to stay longer on the website
• Get visitors to interact more with the site
• Get visitors to engage in a promotion by providing an email
  
• Get more visitors to buy from the site

Split testing also helps ensure that when it comes to advertising, you are maximising each and every dollar. If your website doubles its conversion rate from 1% to 2% using split testing techniques, you have just doubled your revenue using the same marketing budget. You will be able to spend more on advertising your site and earn a better return on investment (ROI) from each dollar you spend. Sounds like you’d be crazy not to, doesn’t it?

It becomes even more exciting when you start to examine the numbers. Many untested websites have conversion rates that run around 0.25%. This means that it takes 400 visitors to get one sale. With split testing, you don’t need to increase the number of visitors, just the rate at which they convert. Many success stories tell of conversion rates upwards of 10%. That would be the equivalent of a 40-fold increase in visitors, all of a sudden giving you 40 sales or sales leads out of 400 visitors, instead of 1.

Who Should Be Split Testing?

Ideally, the web designer should start split-testing as soon as the site launches, as they are the ones who have designed the site and have all of the source files on hand. Even if the owner feels that the website is performing well enough, the benchmark for "good" performance could be moved even higher through using split testing. Just keep in mind that split testing does require an established traffic flow because you need people visiting your site to be able to split-test web pages.

Why is it ideal that the designer does it at the launch stage? Because it is much easier to keep the site as a work in progress after launch, not only visually and structurally, but in terms of its goals. It is infinitely harder for a third party to come along later and change things around, and in many cases, you wouldn’t want them to. That site’s your creation!

Doing the split testing yourself, as a designer, also gives you a real-world feel for what elements will work and what ones won’t. It adds an extra dimension to your sense of aesthetics, removing the guesswork that you necessarily engage in during the design phase. You are no longer doing what you think will create conversions, but implementing what you know produces measurable results. And this knowledge alone will increase the value you bring to your future projects.

Define which element you want to test. In A/B testing, you’ll only test element one at a time. Commonly tested elements are the headline, sub-headline, opening paragraph, image, call to action, and the submit button (look and/or placement).

These are the most commonly tested elements of a web page:

• Headings
• Sub-headings
• Opening paragraph
• Images
• Call to action
• Offers
• Hyperlinks
• Submit button
• The location of different elements
• Colors

The first six elements are the ones which generally have the most impact on conversion rates, and the ones you should test first. Google once tested 41 different shades of blue for their pages. They have the luxury of doing this because they get more traffic than any other website, and they have the drive to do this because performance is their life. They thrive on it! You don’t need to go to this extent but if Google places so much value on it, shouldn’t you?

Knowing When a Split Test is Finished

The number of conversions needed to garner a reliable indication of future traffic varies incredibly with different types of sites. If the business you are designing for is a high-customer volume, low-value spend store, you should test until you have 70 or so conversions for one variant. If it is a low-customer volume, high-value spend store, aim for 20 conversions.

If the set conversion is further from becoming an actual "profit" for the store (i.e. a conversion creates a lead from a visitor, rather than a sale from a lead), you may want to be more certain that one variant is working better than the other. You may also want to test more different variants of the same element, or do multivariate testing … within the limitations of your traffic volume.

Determining statistical significance at the conclusion of a test

For you to have a high confidence level that the test results aren’t just a fluke, you can apply a simple formula to determine whether the difference in results is statistically significant. This rule is:

The numerical difference between the two results must be greater than the square root of the sum of the two results.

Or

Y-X>√X+Y, where Y>X

Sounds like a nightmare from before your high school maths exam, doesn’t it? It is easier to understand with an example:

• If the result of page A was 20 conversions, and the result of page B was 30 conversions, then the difference between the two is 10.
• The sum of the two results is 50
• The square root of that sum is 7 (rounded down)
• The difference (10) is greater than the square root of the sum (7), so the result is statistically significant.

If the two results had been 22 and 28:

• The difference between the two is 6
• The sum of the two results is 50
• The square root of that sum is 7 (rounded down)
• The difference (6) is less than the square root of the sum (7) – the result is not statistically significant.

If the results of your split test are not statistically significant, you can either:

• Keep testing and see if a more definite pattern emerges
• Decide that the element doesn’t make a difference to conversion in this case, and test something else.

Tips for Ongoing Split Testing

Either you, as the designer, or the website owner, should be implementing split testing constantly, on all your high traffic web pages. It takes time to get test results, and in the meanwhile customer preferences and market sensibilities are changing, along with the season and your stock.

It is important to note that not all split tests will be successful. In fact, if you have a 20% success rate where one in five split tests improve the overall conversion rate of the site then you are doing well. The key point to remember with split-testing is that every success forms a new baseline, with considerable website performance improvements achieved after a number of different split tests.

The easiest way to manage all of the split tests is to set one day per month when you review results and then set up tests for the coming month based on those results. Every month you should track your results in a spreadsheet to avoid accidentally re-testing the same elements over and over again. This also provides a point of reference for when you are starting new projects – you can see which placements and copy types are most effective in which industries.

And don’t forget to check what competing sites in the same niche are doing, and test the same elements on your site!

Once you start split testing you’ll find that what you thought would perform better doesn’t and you’ll be very surprised with some of the results. The best part about split-testing is that the confidence you will gain from split testing will help you with your future web sites because you will have an increased knowledge of what produces results and what doesn’t. Consumer behavior is a specialized field and web designers can get on a steep but exhilarating learning curve for it by engaging in split testing on their own and their clients’ websites.

Try WebFormOptimizer today!