Consistency in Web UI Design

How to keep your software’s UI consistent when many programmers are working on the project.

In a development team with half a dozen programmers all working on the same project, creating a uniform user interface can be a nightmare. There can be problems ranging from inconsistent use of icons to language (e.g. formal vs. informal). So the question is, what’s the best way to achieve a cohesive user experience?

Few would argue the importance of UI design these days, especially since companies like Google and Apple have spoilt users with dazzling almost joy-to-use interfaces. But a functional application is still more important at least initially, you can always pretty things up once your software actually works.

When working as a UI designer, it was my responsibility to create mockups for the application being developed. Once I had created the HTML and image files in Web Expression and Photoshop, all I needed to do was bring them into Visual Studio as Master Pages. This worked out great because the programmers would then come along and add the logic.

This turned out to be an excellent approach since it doesn’t require a style guide or volumes of documentation. It works because just one person was in charge of the UI design. The reality is most companies don’t hire someone specifically for a UI role, although more companies are starting to (compared to a few years ago).

Having worked as an IT project manager for a few years now, I have found there is another approach which works well for ensuring UI consistency. Personally, I don’t put much faith in writing UI guides and expecting programmers to follow them. There’s a few reasons for this: 1) programmers often aren’t good at UI design, 2) it’s a lot to remember, and 3) its counter-productive.

UI style guides slow down programmers because you are expecting them to be good at something which they aren’t geared for; they are good at coding, so let them code.

So what do you get when you let programmers do their thing and just code with no specific guidance on UI? Inconsistencies in the interface. This even happens when you provide programmers with mockups to work from. For example, your mockup might not contain the exact wording for an error message so a programmer, quite rightly, proactively puts one in (e.g. “Invalid input”).

What’s the solution? Easy, you have one person review the entire interface at milestones and log bugs in the issue tracker. These bugs would be marked as UI or low priority. If there’s a script error in the software, it’s obviously more important to fix that first before looking at a UI glitch.

The next question is, who should be doing the interface review? It should be one person only (for consistency sake), and that person should be whoever is the most talented with HCI/UI design.

My point is this, don’t make programmers try and be UI designers. When you log a UI bug, it’s there in the issue tracker, it won’t go away. The programmers will come and fix them when they are good and ready. UI bugs are generally easy to fix so they can act as a good break for a programmer. Imagine a coder has just spent 2 hours debugging a serious data corruption issue. Fixing a few UI bugs would most likely come as a welcome relief.

As far as language or wording in an application goes (e.g. error messages, online help, labels, etc), you wouldn’t necessarily need to log bugs for that. If you are using a string table, or some kind of configuration file like XML, then it’s easy for the UI person to tweak text by directly accessing the configuration store. For example, if you found “login error” in the configuration XML file, you could change that to “the username or password you entered is incorrect”.

When things get written down they will be forgotten. This is especially the case when documents get long (e.g. 20+ pages). The problem becomes compounded when you realize that programmers could care less about consistent UI across all the screens of an entire application. Their task lists often say ‘Code login screen’, not ‘Code login screen – and make it look pretty’.

As a side note, I should say I have written a massive UI style guide for an application I designed. It took me almost 2 weeks to write and personally I think it was unnecessary. It was basically a way for programmers to understand how to modify the interface once I finished my contract. As to whether they found the guide useful or not, I don’t know. I think design should be left to designers and coding should be left to programmers, it just makes good business sense.

Author: Louis Marshall