What is Design?

So we know we're not just designing  interfaces, we're designing interactions.   We're not just designing interactions,  we're designing interventions.   That's your job. However, what do  we mean by design? What is design?   This is one of those things that there'll  be 50,000 answers to this question. I'm going to give you one but  hopefully it's one that's helpful.  

So I'm going to say, first of all, that design  is about achieving goals within constraints.   So there's some sort of goal or purpose that  you're after. In interaction design that might   be about an enjoyment goal for people,  about giving... having somebody in   to be able to see a film or be able to listen  to music. Or to be able to engage in a social   relationship. It might be a work goal  like achieving something efficiently,  

being able to produce videos easily. But there's a goal there. And this is true   probably of design in general. Even if you're  designing pure art, you have some sort of goal, which might be, again, it might be aesthetic  or it might be about helping people understand meaning. There's a purpose that you have there. And it's about trying to achieve that purpose. However, there are constraints to that. You  do not usually have total freedom, otherwise   you become a magician, not a designer. Those constraints are critical.

Some of those design constraints might be about the kinds of medium that you have to work with. If you're a painter, whether you're using oils  or watercolors, but as an interaction designer,   it's about your computers that you're using,  what kind of device somebody is likely to have.   What kind of platform they're on. Is it for an Apple or an Android,   if it's for a phone or something else? These are  sort of broad questions. And sometimes you might have choices on those. So that becomes part of your design remit, to make those choices. 

Other times they're given to you. This  is going to run in this organization and   everybody has this kind of computer, full stop  [period]. There's also constraints about time   and money. What's available to you? You do not  usually design with unlimited money or time.  You make choices there. So because  there are constraints, you have to   make choices and trade-offs between some of your  constraints. But constraints are usually given.  

So the trade-off you often have to make is  between different goals and purposes.  Which of multiple goals are you going to achieve?  If I'm designing some video editing software,   I want to make it obviously  as pleasurable and enjoyable   to use by the person editing as I can. I don't want them to have a horrible job. However, I also might want to produce the highest-quality video that is possible, because that's going to improve the experience ultimately of a person like yourself watching this video.  

It could be that I have to trade these off. I have to have something that's going to take   more effort and possibly not very interesting and  enjoyable effort by the person doing video editing   in order to produce a better quality for you.  There is a trade-off. I cannot usually achieve   all of my goals and constraints. Trade-offs are essential to design.   The second of those constraints, one of the core  constraints you have is your materials.

In an art setting that might be about the kind of paint  you're using or what you're using, whether you're   painting or whether you're doing sculpting. Clearly that makes a difference. If you're a sculptor and if you're using stone or wood, that is going to change the nature of what you produce.   This is also true of physical design, and  it's also true of interaction design.  So in a physical sense, I often – I won't do it  now – but I can lift up chairs and things like this and say, ah, look, this chair is made of  metal.

If you take the design of a chair that's made of metal it will often have thin legs. If you make that in wood, the legs would break. But similarly, if you take a wooden chair, that's  a much more solid one, and made it metal, it would probably be too heavy to move. The materials  used change the fundamental nature of design. That's true of physical design, but it's also  true of digital design. You have to understand   the nature of materials you're using. So if you  design something that is initially designed for  

a desktop computer and just take the same design  and squash it into a phone, it won't work. If you take a design that is designed for  your phone and then try and put it without   sufficient changes onto a voice interaction, it  won't work. You have to understand your materials.   So what are your materials? I've already given you some of them,   the kind of platform you're on. Your computer  is part of the materials. You have to understand  

the nature of what's possible. Some of  that's obvious, like the screen size,   the thing I was just talking about. But also, what computation is possible? Say you're   the designer, you're not a builder yourself. Say  to the person who is actually constructing this:   "Oh, this this has to work like this. Is that  possible?". Or are you making things so difficult   that you will cause problems elsewhere? What are the fundamental capacities of it? You cannot, for instance, ask that for an interactive  video, that you have instant-millisecond

timing between two places, distance on the Earth,  because the speed of light constrains you. There are constraints and capacities like that,  but also storage capacity. How much video can   you store on a computer? That's a limited  amount, depending on the kind of device.   The kinds of tools you've got to use,  the kind of platforms you're on... All of these are part of the material that's  available to you as a designer.

Now, it might be that some of the details of that are done by other people, but you have to design something that works within those constraints.You have to understand the material,   the digital material. But of course, you also  have to understand people. The other aspect of   it is the people, the other crucial aspect. So  you have to understand the nature of people. Otherwise, you can't design for them. People are  part of your materials. You have to understand   their psychology, their social nature. And of  course, these extra things which are complicated  

about the interaction between the people and  technology and between people and each other. So you have a rich picture of materials.  Now, you might be starting to think – and   as I say "materials" and then I put  people into that picture – you might   have been comfortable with me saying "your  computer is a material". Of course... But people as your material, surely that's a  little bit functional way to think about people?  

Well, it is. People are not a material in  the same sense as the paint you choose when   you're painting or whether you choose to  use stone or wood when you're carving. It's not the same. People have  individuality. However, what we say   is that if you only treat people as well as you  treat materials, you probably treat them better   than they are often treated in design. So we  treat people at least as good as materials. I'll explain why. How many times have you heard  there's been a big accident, whether it's a plane  

accident, train accident or something like  that. People say, "Oh, it was human error,   it was due to human error". The person didn't do the right thing at the right point. They didn't notice something  that was important and things went wrong. You might have said it. It might be in a  hospital situation, industrial situation.   So just imagine instead the wing falls off the  plane because there's metal fatigue where the  

wing joined the plane. Now you would say it was due to the metal fatigue, but you wouldn't   say "it was metal error". You would say "it's a  design error". Because the designer of the plane,   the engineers, the detail designers would have  had to – should have – understood the nature of   metal and the fact that you do get metal fatigue  after a while. You should either design it so that where there's metal fatigue, it doesn't  fundamentally mean the plane will crash.  

Or you design it so that you can detect  when that metal fatigue is happening   and then take preventive maintenance.  There are a number of strategies you've got   because you understand that metal as a  material has known ways of failing. We as humans have limits and  constraints and ways that we   fail in the sense we don't always do things in the  perfect way. Just like a piece of metal doesn't.   As a designer your job is to understand those  limitations of people as actors in the system.  

And ensure that the design of the system as a whole works even when those happen. So whenever   you hear about human error, it was human  error. But typically, it wasn't the operator   or the pilot or the nurse or the doctor in  the hospital. It was typically the designer   of the system that's there. If you treat users as well as a piece  

of metal. You are probably dealing with them  a lot better than they usually are dealt with.   So having said that, let's just roll back and  come back to what's the central message here? The central message is that for you as a  designer, the user is at the heart of what you do.   Understanding your users,  and you have to understand   the technology you work with, but understand  those users, understand the nature of them. And as I said, then you'll start to treat them  far better, hopefully, than a piece of metal.