 Multi-element design, multi-element design, multi-element design, multi-element design, multi-element design, multi-element design, multi-element design. This is just an alternating treatment design. Bye. We have a video on that. You can go watch it. I'll probably do it before you again. You want me to do it again? Fine. I'll do it again. It's really simple, folks. It's multiple elements, right? So, in this case, we have an A-condition, a B-condition. You might even throw in a C-condition. We're not going to worry about that. We'll just work with A-B, alright? So, we're going to alternate between those two conditions. So, that's why people often call it an alternating treatment design. Anyway, so let's, you know, better example. We'll go A-B-C, alright? So, we could do a design where we have an A-condition, then a B-condition, then a C-condition. Back to a B, back to an A, back to a C, back to an A, back to a B, back to a B-A. And in an A-B, A-C, A-B, B-A, C-A, C-A, B-A, B-A, B-A, B-A, C-A, B-A, C-A, B-A, C-A, B-A, C-A, B-A, C-A, B-A, C-A, B-A, C-A, B-A, C-A, B-A, C-A, B-A, C-A. Just make sure you compare the A's with the A's and the B's with the B's and the C's with the C's. You're going to get a lot of different conditions. You only need... Normally, we have a stability requirement before you switch conditions. With a multi-element or an alternating treatment design, you don't have that. All you want to do is change the condition and then get one picture, like one snapshot of behavior. Then you change the condition, get another snapshot. Then you look over time to see where all the A's are relative to all the B's relative to all the C's. So again, take a look at the alternating treatments design. It's got a pretty cool example in there too.