I want to use this blog post to dig a little bit deeper into what I think of as the inherent contradiction in talking about aesthetics vs. usability as two separate things and to propose instead that we started thinking about product designs in terms of the effects they produce that can be measured vs. those effects that can't. Any effect that can be measured can at least be analyzed and its importance prioritized relative to other effects that we may also be seeking to produce.
The second to last sentence in Mark Boulton's article highlights the contradiction:
Good usability is inherent in good design because people think well designed things work better, whether they do or not.
The only way in which this sentence can make sense is in a world in which the concept of "work better" is artificially circumscribed. Mark's intent is to defend good design, of course. I just think he doesn't quite go far enough. He uses the analogy of a car, and I think it's a helpful one.
Take, for example, a Honda and a BMW. Does the BMW have a "smoother ride"? Probably. Is that an aesthetic issue? I doubt many people would describe it that way but yet what is the practical effect of a smooth ride? Are there any? Are slight vibrations bad for your health or do they adversely affect your ability to navigate the car? No. However, many people would agree that a smooth ride is a good thing. Can you measure smoothness? Yes.
Actually, you could potentially measure it in two ways:
- You could measure the frequency and magnitude of the vibrations at some particular point in the car, and/or
- You could measure the effect of the vibrations on a driver sitting in the seat via some representation of their emotional response like skin conductance, eye blink rate, pupil dilation, or other sci-fi type methods that are actually in use within many usability labs of large companies
The first method of measurement is well known and is assuredly used by car manufacturers and so "smoothness of ride" is probably not considered by anyone in the industry as an aesthetic issue.
How about the way the car looks. Does the BMW look "better" or at least "different"? Yes. Unfortunately, there is only one way to measure the effect of the visual design of the car and this is through the sci-fi methods mentioned above. Does that make it less real? Of course not.
So, a "smooth ride" is a pleasant sensation so is looking at cars that have visual designs that appeal to us. What's the difference between the two? None. People will pay good money for both sensations. People will refer a car to their friends based on both sensations.
So what's the point of talking about aesthetics on the one hand and usability on the other? I don't see it. I think the only reason that the dichotomy exists is that the measurement of emotional response is a recent development and is not widely appreciated.
It seems to me that if all of this is true with cars then it must be especially true with web sites and software since most of our experience with these products is processed visually.
Of course it's possible to create elaborate visual designs that do not elicit a meaningful emotional response. Don Norman has article (Emotion & Design: Attractive things work better) in which he examines two different tea pots to understand what impact the visual appeal of the tea pot has on its "usability". Personally, the tea pot designs don't do anything for me. I think the more visual processing involved in our natural interaction with a product, the more emotionally powerful good visual design can be.
When visual design is bad enough, of course, we see people do things like squint their eyes and furrow their brow and then people usually feel comfortable using the word "usability" in this case. But this is just a difference in the degree of the problem, not a difference in the fundamental type of problem.
I've started reading a very good book, Measuring the User Experience, by Tom Tullis and Bill Albert, that discussed methodologies for, well, measuring the user experience. The book covers a fascinating range of topics including ways to measure facial expressions, track eye movements, puillary dilation, etc. Yes, all this can actually be done at this point.
They also cover much more prosaic approaches like testing whether someone successfully complete a predefined task.
What strikes me about this is that their definition of "user experience" is so obviously a superset of both "usability" and common definitions of "visual appeal". So, this has got me thinking... is there really a meaningful distinction between usability and aesthetics at least with regard to software and web design?
In my first blog post I sited a 2009 study by Christine Phillips & Barbara S. Chaparro that looked at the impact of visual design on perceptions of usability. There are a number of blog posts and articles that explore the interrelationship between aesthetics and usability but the most widely read and one of the earliest was Mark Boulton's 2005 piece: Aesthetic-Usability Effect.
As the first sentence in Mark's article states:
The Aesthetic-Usability Effect is a condition whereby users perceive more aesthetically pleasing designs to be easier to use than less aesthetically pleasing designs.
My problem is that the definition of aesthetic is this:
pertaining to, involving, or concerned with beauty, emotion or sensation as opposed to pure intellectuality
So, the discussion is already ridiculously muddied by these definitions since to say something is concerned with sensation is a meaningless statement. What isn't concerned with sensation? You sense your brakes have failed or that the car has just crashed into a telephone pole. Ok, so toss out that part and let's focus on the other parts of the definition.
Even the other parts are problematic because they are conclusive statements. Using the above definition, we most definitely cannot equate the terms "visual appeal" and "aesthetic appeal" since we know that aspects of visual appeal (i.e. font or color) can impact usability and the definition of aesthetic relates only to beauty.
Until you do some testing, you really have no idea if the changes are "purely aesthetic" in nature. The choice of font or color can obviously impact the usability in the extreme.
I think many visual or sensual elements of a product that have real "usability" implications are misunderstood as being "purely" aesthetic in nature or in their appeal. For example, I think it would be difficult to find any aspect of the design of Apple products like the iPod, iPhone or iPad that were purely "aesthetic" in nature, according to this strict definition.
So why is there a debate at all?
I think it's because determining the usability impact of many design choices or various visual elements can be time consuming and tedious and involve regression analyses and so forth. Why is it so time consuming and tedious? Because cognition is largely a black box and optimizing design often involves a lot of trial and error. In addition, the available options are usually not well defined and most people don't have a very good vocabulary for talking about them.
Here are some thoughts on how one might be able to structure a cheap test to explore the usability implications of purely aesthetic variations. Maybe "usability implications" is a bad term since there is a commonly accepted dichotomy that places usability issues on one side and aesthetic issues on the other. I'm not sure what other word to use and I think placing usability on one side and aesthetics on the other is a "false dichotomy".
The methodology is for a cheap test in the sense that I think it can be meaningful even with a handful of participants. Here's how it would work:
- Have a user perform a "control" task like finding the lowest available priced KindleDX, including shipping, available to be purchased immediately on ebay.com. Time their performance of this task.
- Then take them to one of two different versions of a similar site, like ubid.com. For some people, take them to the regular version of ubid.com (Figure A). For others, take them to a more aesthetically suspect version of the site (Figure B). Ask them to perform the same task (finding the lowest available priced KindleDX, including shipping, available to be purchased immediately) and time them again.
There is a Google Chrome extension called Chrome Sylist that allows you to define local CSS files that override the CSS defined within the HTML code. It's a pretty cool tool, allowing you to define a general override for all websites, an override for specific domains and an override for specific web pages on specific sites. This might be kind of a nice thing to install for a parent or grandparent that has trouble with readability on certain websites, maybe issues that aren't easily addressed simply through the browser's zooming function.
I'm not entirely sure what it was designed for but it's certainly also very useful for testing usability with public websites whose styling you don't otherwise control.
I'm proposing that you could look the users' timed performance with ubid.com relative to their timed performance with ebay.com. Obviously, some users take longer than others to perform tasks but you can still compare users with varying levels of speed, computer facility, etc. with each by using this relative measure of performance.
I suspect that what you would see is that users who use the Figure B version of the ubid.com site will have longer tasks times relative to their ebay.com task times.
There are certainly non-task oriented sites where timing test are either difficult or impossible but I think that testing task oriented sites in this way can at least establish a few base level design principals that can perhaps be extended into areas where testing isn't possible.
There was a 2009 study by Christine Phillips & Barbara S. Chaparro entitled Visual Appeal vs. Usability: Which One Influences User Perceptions of a Website More? that looked at perceived usefulness and satisfaction for both low-appeal and high-appeal web sites. They varied the usability of both sights and observed what affect the variations had on user satisfaction and perceived usability of the site. Basically, they found that the perception of low-appeal websites did not improve much, even with objective increases in usability.
I'm wondering if an attempt has ever been made to study the impact of aesthetics on usability with respect to efficiency in completing tasks. The time it takes to complete a basic task seems like a pretty reasonable measure of how usable a site is, and I think the activity could be defined both in terms one-time tasks as well as repeated tasks.
The idea would be to site people down and ask them to perform the activity on two versions of a site that are functionally identical. One version exhibits poor aesthetic design (maybe inconsistent fonts, etc.) and the other exhibits good aesthetic design.
My suspicion is that it would take participants slightly longer to perform tasks on the site with poor aesthetic design because of eye fatigue, weariness, etc. I think we instinctively know these can be the effects poor design but I haven't seen a study specifically structured in this way.
Please let me know if you're aware of one.. Thanks.
