[MUSIC] Virtual reality interaction isn't just about making technology usable. It's about creating presence. It's about grounding us in the virtual world we are creating. To do that, you should create interaction that's as close as possible to how you interact with the real world. In virtual reality, you shouldn't base what you do on games or film. You should base it on the real world. But there are two big caveats. The first is that your interaction must be usable. While you're trying to make interactions as close to the real world as you can, there might be ways in which it's different, and that can make it hard to use. You need to make sure it's clear how to interact with the world. Sign post clearly what people can do and what they can't. If they can interact with an object, make it look subtly different to an object they can't interact with. Design your objects so it's obvious what you could do with them. Psychologist JJ Gibson said that we can see what actions we can do with an object just by looking at it. What he called affordances. The handle of a cup, affords picking up, a door knob affords turning, a well designed object has clear affordances. If you need to pull a door to open it, provide a handle. If you can't make it obvious just by looking at it then give clear instructions, at least for the first time a player is going to use it. If an action has to be done a particular way, for example, you have to do a gesture in this way and not that way for it to be recognized, then make that very clear and explain it. Otherwise, you're going to create a frustrating experience. And provide feedback that you're doing an action properly. Objects need to respond straightaway when you do something to them. That way users can know if they've done an action right or if they haven't. Sometimes there just isn't a natural real-world interaction that corresponds to what you're doing. So a traditional graphical user interface might just be better. For instance, it might just be better to have a menu. The other things to think about is that although realistic interfaces can be great, magical interfaces can be even better. Slightly extending what we can do in the real world can make our interaction easier, and more powerful. So the rule is you should base your interaction in the real world, but you can also sneak in something from a super hero movie. You just have to remember that it might make the experience less plausible, and so give people less presence, which is something to be careful about. So there are lots of exciting interaction techniques you can use in virtual reality, to create fantastic experiences. But the last word of advice is that none of these will automatically work. To know if it works in your experience, you really have to test it. Test it yourself, test it with your friends, test it with people as different from yourself as you can imagine. If you are young, test it with older people. If you are a woman, test it with men, if you are gamer, test it with non gamers. If you are physically fit, test it with somebody who has difficulty moving. But most of all, just test it, test it, test it. And that's the way to get great interaction. [MUSIC]
