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.