Non-designers are often called upon to make judgments about interfaces. Perhaps you are a business owner evaluating your new website, or a project manager looking at mockups from your designer. What do you look for in the design? And how do you give feedback in a more meaningful way than “It looks nice” or “It seems hard to use”.

While the full-depth of understanding design cannot be covered in a short article, here are some guidelines to help you out.

To get you started, here is an example of a critique I recently did of the interface for the yet-to-be-released Add-On Builder* for Firefox. The Add-On Builder is part of the Jetpack project and is a web-app of medium complexity that allows you to easily build Firefox and Thunderbird extensions online and then publish them to the world. I took screenshots of each screen of the interface, put them into one large document, and commented ex vivo.

When are you critiquing?

The first factor in how you critique is determined by when you are giving it. If you are reviewing an interface just before a product or website launches, there won’t be enough time for your feedback to have a big effect and you’ll have to give smaller-scale suggestions. The earlier you can review the product, the more impact your words will have.

The User’s Train of Thought is Sacred

Look for things that break the users train of thought: any time they have to think about how to use your product and not what they are doing, your interface is frustrating them. Modal dialog boxes, confirmations, settings screens, anything that requires them to think about more than one thing simultaneously, and filling out unnecessary forms before being are allowed to enter the site, etc. All of these things get in the way of the user actually using your product.

Reduce Interaction

The goal of interface design is to get rid of the interface. While interfaces with lots of interaction can look snazzy, you’ll have fewer usability issues when you minimize the amount of work someone has to do to use your product. You know those news sites where the articles are paginated into tiny chunks so that you keep having to hit “next” just to wait for dozens of ads to load? If you are like most people, you hate them and often never finish reading the article. That’s interaction overload at work.

Think long and hard about every little step a person has to do to use your product. Write them out. If you get fatigued, you know you need to simplify.

Visual Placement Matters

Make sure that your buttons, links, and actions are logically grouped. Often you will see interfaces with “save” right next to “close”, meaning a little user mistake can cause dire repercussions.

Beware Too Many Icons

Icons can be difficult to understand, even while they look pretty. Users often have to hover over an icon each time they want to use it to discover what it means. Instead of using an esoteric hieroglyph, use text to say what you mean.

Give a Good Starting Point and Keep Consistent

The best interfaces are incrementally learnable: you shouldn’t have to tackle a fifteen-minute seminar before you can do a basic task—you should be able to just learn the one thing you need to do and be on your way. Does your product give a good indication of where and how to start? And is what you’ve learned should be applicable in helping you learn the next thing. Keep the mechanisms simple and the metaphors consistent.

Fewer choices mean fewer worries

Try to avoid burdening your users with choices on how to perform an action. Giving them lots of options may seem like a good idea but it isn’t. It ends up bloating an interface and burdening your users with decisions they shouldn’t have to make. If you see more than one way to do something, ask the designer to take the time to make one simple mechanism that the user can use for all their purposes. Don’t just dump an indecision into a preference. The less burdened a user’s mind is with irrelevant decisions, the more clear their mind is to accomplish what they need to get done.

Look is Important. Interaction is More Important

The look of a product often gets much more attention than the “how” of a product. Avoid the trap of spending the bulk of the time on look: it’s like rearranging the chairs in the Hindenburg. Look is much easier to change and polish, and it is much more apparent when something is broken. Interaction is the heart of your product—spend all of your time making it act right and at the end make it look right.

More

For more information continue reading this blog or the following books and blogs:

• The Humane Interface by Jef Raskin
• First Principles of Interaction Design by Bruce Tognazzini*
• 10 Heuristics by Jakob Nielsen*
• The Design of Everyday Things by Don Norman
• Understanding Comics by Scott McCloud
• The Resonant Interface by Steven Heim
• Don’t Make Me Think by Steve Krug

For the designers out there, what resources would you recommend? If you’ve got some I’ve undoubtedly missed, please leave your suggestions in a comment.

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