Consistency in Design is the Wrong Approach
September 15th, 2005
Current Knowledge is a much better way to think about the problem.
Consistency in design is about making elements uniform — having them look and behave the same way. We often hear designers talk about consistent navigation, consistent page layouts, or consistent control elements. In each case, the designer is looking for a way to leverage the usability by creating uniformity. After all, if the user learns to operate the design in one place, why not have that knowledge transfer to the next. This is all good. But wrong.
For example, let’s look at the problem I discussed a while back by our friends from Avis.com. They chose to use the asterisk (*) to denote optional fields instead of denoting mandatory fields. Less than 10% of the fields on the entire site are optional. If they were consistent with the outside world, entire forms would have every field denoted with an asterisk. That might create its own problems.
So, Avis.com’s designers do what designers are supposed to do: they made a choice. They chose to be inconsistent with practically every other form on the web. But they were internally consistent with themselves.
The problem with thinking in terms of consistency is that those thoughts focus purely on the design and the user can get lost. “Is what I’m designing consistent with other things we’ve designed (or others have designed)?” is the wrong question to ask.
Instead, the right question is, “Will the user’s current knowledge help them understand how to use what I’m designing?” Current knowledge is the knowledge the user has when they approach the design. It’s the sum of all their previous experiences with relevant products and designs.
If the designers at Avis had asked, “Will the user know how to separate optional fields from mandatory ones?” they would likely have come to the conclusion that using asterisks to denote optional fields might confuse a user or two. They could’ve used a different typographic or visual solution, or resorted to the old-tried-and-true “(optional)” text next to the appropriate field label.
When you think about consistency, you’re thinking about the product. When you’re thinking about current knowledge, you’re thinking about the user. They are two sides of the same coin. We’ve just noticed that the designers who spend more time thinking about the users are the ones that end up with more usable designs.
Why do we gravitate to consistency? Because it’s easier to think about. You don’t actually have to know anything about your users to talk about making things consistent. You only have to know about your design, which most designers are quite familiar with.
Current knowledge, on the other hand, requires in-depth knowledge of the users. And that takes research time and investigative effort. It doesn’t come cheap, like consistency does. But it produces much, much better results.
Funny thing about thinking about current knowledge: when you’re done, your interface will feel consistent. Why? Because it will match the users’ expectations and, where they expect it to behave like something they’ve encountered before, it does.
(This has the interesting side effect of reinforcing the wrong thing. When you run into a site that feels consistent, you’re not likely to say, “Hey, those designers did a good job because they obviously researched what my current knowledge would be.” Instead, you say, “Hey they made things consistent. We should do that.” Thus, the cycle of poor practice is reinforced…)
My recommendation: anytime someone on your team starts talking about making things consistent, change the conversation to be about what the users’ current knowledge is.
September 16th, 2005 at 8:27 pm
[...] Stephen Downes points to a great article that argues that designers often focus entirely too much on the consistency of design versus thinking about a users current knowledge. The problem with thinking in terms of consistency is that those thoughts focus purely on the design and the user can get lost. “Is what I’m designing consistent with other things we’ve designed (or others have designed)?” is the wrong question to ask. [...]
September 23rd, 2005 at 8:47 am
I am curious about a couple of items.
Car companies usually are thinking of their customer’s “curretn knowledge” in creating new design. While it adds sparkle to their line of products, it tends to narrow their customer base. Yet, underneath it, there seems this shadowy consistency: design by customer wants. But which customer?
Secondly, does this tend to exaccerabte the problem of constantly changing to meet the whims of customers, reinforcing an eclectic approach to life rather than attempting to build foundations? I’m not advocating a “stone age” approach to life (i.e. everything is in concrete and can never change). No, consistency provides a framework, an identity even a sanctuary. Some consistency, I think, it vital. Addressing customer needs and wants to important too and I support researching customer knowledge as a key means of delivering the product. But I also think some dynamic balance (i.e. a consistent concept applied upon customer knowledge) would be good, too. Example: pants; still fit over two legs but look at the pockets!
October 10th, 2005 at 11:13 am
I’m a bit confused by this article. The headline is provocative, but the article doesn’t argue that consistency is a *bad* thing. Rather, it seems to state that being internally consistent is not sufficient for good design, if the design choices were poor. Is this the crux of the article? I’m not sure exactly how the Avis example makes sense in this context…it seems that if the Avis designers had elected to be ‘externally’ consistent (using asterisks) perhaps that would have been superior to creating their own standard and foisting it on users.
October 10th, 2005 at 11:55 am
Patrick: What I was trying to say was that consistency isn’t bad, but is the wrong place to start when designing. When designers ask, “What should this be consistent with?”, they aren’t necessarily taking the users’ knowledge into account — thereby creating something that is consistent but unrecognizable.
The AVIS folks shot for internal consistency, however they didn’t take into account that many users would come with an already existing perception of what the asterisk meant — the opposite of the designer’s choice. The result: confusion *because* of the consistency.
Instead of focusing on consistency, the right place to start is “What do the users know?” If users are familiar with design elements, and you design for that familiarity, you’ll end up with a consistent interface. But, that’s really an accidental side effect of designing for current knowledge.
October 10th, 2005 at 12:00 pm
Dave: We like to turn to personas when we’re faced with the “Which users should we design for” question. Personas take an umanagable mass and focus it on a few individuals with both overlapping and independent needs.
November 20th, 2006 at 2:48 pm
Thank you for this validating article. As a user interface designer I have never been more frustrated than when I’m sitting in a “Design by Committee” meeting and some well intentioned, but otherwise misinformed corporate hack comments that “the design should be consistent.”
Really, you think! Consistent with what, may I ask? Consistent for the sack of consistency? Consistent with sounding proper at a meeting when you really have no idea what your talking about?
Whenever someone says “Make it consistent” I usually break out in allergies, because in my experience consistency has been the bail of anything creative and the force that misdirects a design team.
Obviously certain things have to have a uniformity of structure, and a repeating theme in the design, but what they really are saying is, “at all cost, make it an easy project that wont be a problem later.”
It’s a cursed word because it usually has the opposite effect. It’s a word that save you from looking radical in a corporate meeting, (and we all know where that can lead to). It’s a word that fails to address the very fact that “consistency” often times can be equally apply to doing something consistently wrong.
Every company has a nebulous definition of consistency, even when we think we are saying the same thing. Perhaps the word should be banned!
September 18th, 2007 at 11:13 pm
[...] usability consultant Jared Spool recently wrote about the difference between designing for “consistency” and designing for [...]