Note: This was published in ACM Interactions, volume 15, issue 5.

Everyone wants simplicity. The same desires are there whether the device be a new cellphone or a shop tool, the dashboard of an automobile or the choices while shopping in a store. “Why can’t my technology be as easy to use as my garage door opener?” asks one paper on the topic: “one button and it opens or shuts the door. Simple, elegant.”

The cry has been picked up by everyday people, newspaper reviewers and professionals alike. But if it is so obvious, if the need is so great, why don’t the products match the cry? Everyone misses the point. Simplicity is not the goal. We do not wish to give up the power and flexibility of our technologies. The garage door opener may be simple, but it hardly does anything. If my cellphone only had one button it certainly would be simple, but, umm, all I could do would be to turn it on or off: I wouldn’t be able to make a phone call. Is the piano too complex because it has 88 keys and three pedals? Should we simplify it? Surely no piece of music uses all of those keys. The cry for simplicity misses the point.Just look at what people actually buy in the stores, says the marketing expert, people really want features. And yes, that is very true. I made this point in my earlier article on the subject (“Simplicity is highly overrated,” Interactions, March/April 2007). There is indeed an apparent conflict here. As the number of features increase, so too does the desirability of the device. But as the number of features increases, simplicity goes down. As a result, even as people buy the devices with extra features, they cry out for simplicity. Features versus simplicity: are these two really in serious conflict? By standard measures, yes.  We want devices that do a lot, but that do not confuse, do not lead to frustration. Ahah! This is not about simplicity: it is about frustration. The entire debate is being framed incorrectly. Features is not the same as capability. Simplicity is not the same as usability. Simplicity is not the answer.

There is an implicit assumption:

Features => CapabilitySimplicity => Ease of use

These two statements translate into simple logic: Everyone wants more capability, so therefore they want more features. Everyone wants ease of use, so therefore they want simplicity.

Alas, this simple logic is false logic, false because it follows the implications backwards. Suppose I said:

A sunny day ==> it won’t rain.

Does this mean that if it doesn’t rain the day is sunny? Of course not. The arrow goes left to right: this says nothing about the right to left direction. So extra capability does not require more features. Similarly, ease of use does not require simplicity.

I conclude that the entire argument between features and simplicity is misguided. People might very well desire more capability and ease of use, but do not equate this to more features or to simplicity. What people want is usable devices, which translates into understandable ones.

The world is complex, and so too must be the activities that we perform. But that doesn’t mean that we must live in continual frustration. No. The whole point of human-centered design is to tame complexity, to turn what would appear to be a complicated tool into one that fits the task, that is understandable, usable, enjoyable.

Design to the Rescue

We are faced with an apparent paradox, but don’t worry: good design will see us through. People want the extra power that increased features bring to a product, but they intensely dislike the complexity that results. Is this a paradox? Not necessarily. Complexity can be managed.

Once we recognize that the real issue is to devise things that are understandable, we are halfway toward the solution. Good design can rescue us. How do we manage complexity? We use a number of simple design rules. For example, consider how three simple principles can transform an unruly cluster of confusing features into a structured, understandable experience: modularization, mapping, conceptual models. There are numerous other important design principles, but these will make the point.

Modularization means taking an activity and dividing it into small, manageable modules. That’s how well-designed multifunction printers, scanners, copiers, and fax machines do it: Each function is compartmentalized by grouping and graphics, so each is relatively simple. HP invented a common control mechanism (their “Q” control) so the same principles governed usage of all functions. Learn to do one function, you then know how to do all of them.

Good mapping is essential to ensure that the relationship between actions and results is apparent.

But most important of all is to provide an understandable, cohesive conceptual model, so the person understands what is to be done, what is happening, and what is to be expected. This requires continual, informative feedback, which can also be done in such a way as to be pleasurable: see any Apple product.

Emotional design is critical to a person’s enjoyment of a product, the most critical variable here being the need to feel in control. This is especially important when things go wrong. The key is to design knowing that things go wrong, thereby ensuring that people will understand what is happening and know what to do about it.

The argument is not between adding features and simplicity, between adding capability and usability. The real issue is about design: designing things that have the power required for the job while maintaining understandability, the feeling of control, and the pleasure of accomplishment.

Don Norman wears many hats, including co-founder of the Nielsen Norman group, Professor at Northwestern University, and author, his latest book being The Design of Future Things. He lives at jnd.org.Column written for Interactions. © CACM, 2008. This is the author’s version of the work. It is posted here by permission of ACM for your personal use. It may be redistributed for non-commercial use only, provided this paragraph is included.