[MUSIC] In this lecture, we're going to talk about active and passive interaction. Active interaction is what we normally think about when we're interacting with a computer. It is consciously deciding to interact. I decide to click a button on my phone, and I click it. But we also have passive interactions with technology. For example, my fitness tracker will detect when I move anywhere and alerts me when I reach the target number of steps for the day. At no point am I consciously interacting with it as a piece of technology. I'm not clicking buttons. I'm not doing anything to it. It's just detecting what I'm doing in the background. It's doing its thing based on the actions and activities that I'm doing in my life anyway. Virtual reality has a lot of active interactions, picking up objects, moving stuff around. You are choosing to do things in the world, but there are also lots of possibilities for passive interaction. The most basic virtual reality interaction of all, turning your head to look around, is basically a passive interaction. You're not thinking, I'm going to scroll my view of the world as you would on a standard computer screen. You're just doing what you naturally do in the real world, which is looking around. And when you do, the headset responds to you. There are lots of other possibilities for passive interaction. For example, you might want the leaves of a tree to move as you brush past. That's the kind of small response from the world that can really make you feel like you're part of it. It's exactly that kind of little response that creates the plausibility illusion. So as well as thinking about the active interactions that your user is going to be deciding to do and doing, also think about possible passive interactions. The way the world subtly responds to where your user is and what your user is doing. But there are a couple of things you should be careful about with passive interaction. First, it can be a bit creepy. There are lots of stories these days of software tracking us without us knowing, which you could call passive interaction. If your user isn't aware they're doing something, I would strongly discourage you from doing any kind of data collection or tracking. Passive interactions should just be about an immediate response to what is happening. The second issue is you have to make sure passive interactions really is passive. Passive interaction is about things that we don't control explicitly, and we're probably not aware we are controlling our passive interactions. But if you're using a passive interaction for something the player does want to control, the fact that they're not doing it explicitly means they may not know how to do it. In passive interaction this is generally not made clear how it works, so you don't know how to control it. That can lead to a very frustrating experience if you actually want to, say, turn the lights on, but you don't know how to do it. So use passive interaction for the subtle things, the things that don't change the overall narrative, they just have a little effect. If you ever think that a player might want to control something and do something explicitly, make sure it's active and the user interface is very clear. So passive interaction is a really great way of creating plausibility illusion. It's a great way of making a player feel part of the world because the world responds to them. But you have to be careful how you design it, and that you don't confuse it with active interaction. [MUSIC]
