 Clicker training. Clicker training is a great tool that you can use in all sorts of settings, but it was popularized by Karen Pryor in the late 90s. And specifically what you do is use an auditory stimulus as a condition reinforcer in order to strengthen the response from an organism or human for that matter. Specifically, it's a handheld device. It's usually about yay big. I don't have one handy today, but through the magic of TV, we have the sounds. That would be clicking, right? We could pair that click with a food or petting or something like that. And so it would be click, treat, click, treat, click, treat. We do this about 10,000 times. Bear with me. It'll take a while. Treat, treat, treat, treat. And eventually I don't have to use the treat anymore. I could just do this and it reinforces behavior. So through classical conditioning, we establish a condition reinforcer in the following sound by pairing it with a treat. CS, US treat. The sound becomes the condition reinforcer and can strengthen behavior upon delivery.