Where Does the Burden of Proof Lie for New UI Elements?

Paul Boag

As companies, we need to shift our attitudes from “why not” to “why” when it comes to what we put on our websites.

I recently posted to Twitter my dislike of those “download our app” banners that appear on so many websites. I implied that website owners should drop them as they are nothing but an annoying distraction.

Unsurprisingly this got a reaction from Twitter, with many people asking me to justify why they are damaging to the user experience. They wanted hard numbers to back up my claim. Numbers that, to be honest, I did not have.

Of course, this is fair enough, and I cannot blame them. But it did get me thinking. Why should the burden of proof lie with me? Why should I have to justify the need to exclude an element from a website? Why shouldn’t it be the job of those proposing a UI element to justify its inclusion?

The Battle to Maintain Simplicity

I see digital teams struggling with this issue all of the time. They are always fighting with colleagues across the organisation trying to simplify the user experience, but having to battle for every element they want to remove. What is more, they are continually resisting a tsunami of requests to add even more elements.

It is time for us to take a different approach. It is time for us to stop having to justify the exclusion of unnecessary UI elements. Instead, the burden of proof should fall on our colleagues to justify their inclusion. But how do we make this happen?

How to Shift the Burden of Proof

That is where a set of design principles can be invaluable. By formalising the idea that the burden of proof lies with those wishing to add elements, or that every element has to justify its inclusion, we establish a new premise.

Design principles are a useful reference to refer back to in order to stay on track.

In many cases, you will meet little resistance to the creation of these design principles. Statements such as “every UI element needs to justify its inclusion” seems very reasonable in the abstract. People will not necessarily resist it in the same way as they would an argument over a specific UI element.

Justifying the Shift in the Burden of Proof

Of course, that does not mean we can get away with having no justification. Fortunately, there is a solid argument for a design principle such as the one I suggest above. There are good reasons why the burden of proof should lie with anyone wanting to add UI elements to design.

Not long ago I wrote a post on cognitive load. In that post, I explained that cognitive load has a devastating impact on the conversion rate of any website. That when users are required to process too much information they make mistakes and miss things entirely. Worst of all, at a certain point, they give up completely.

The impact of cognitive load can be demonstrated easily by asking colleagues to watch the following video.

We rarely give a website our full attention. Most of us are surrounded by distractions when using the web, from screaming children to having the TV on in the background. Then on top of this, we have the plethora of unnecessary user interface elements to distract us further.

In short, every element we add to a website increases the user’s cognitive load and that negatively impacts the likelihood of them converting.

So do I have data that shows that those “download our app” bars have a negative impact? No, I don’t. But I do know that every element added to a website will contribute to a user feeling overwhelmed.

The impact of cognitive load means that every element has to justify that the benefit it provides outweighs the damage additional UI elements cause. That places the burden of proof squarely on the person proposing the new UI element.

But What About Hard Data?

Do not misunderstand me, having data is extremely useful. But often when people ask for data, it is merely a blocking tactic to force you to justify your position because they disagree with it. By establishing a design principle backed up with what we know about cognitive load we shift that burden of proof.

The problem is that establishing a direct correlation between the addition of yet more screen elements and a decline in conversion can be harder to do than measuring how many people clicked on a “download our app” link. That is why we need to recognise the limitations of data and instead learn from the more general principles of behavioural psychology, and the impact of cognitive load on human attention.

Time to Create Those Principles

Hopefully, this gives you one more reason to create some design principles and a digital playbook. If you continue to put it off, you will spend the rest of your career arguing over every little improvement you want to make to your website.