 Ah-ha, wow, external validity, I don't know why that's funny and you need the scary voice for that, but I'm scary laugh for that, but I did. The degree to which a study's findings generalize beyond the study itself, external validity, is it gonna happen in the real world? And even but that's like extreme external validity, and we could have external validity, it's going to happen in the other lab, the one next door, or oh yeah, how about with different subjects? Oh yeah, how about with that other lab down the street? Oh yeah, how about that lab up down in Alaska? You don't want, it's cold up there folks, lots of up downs. So does the experiment generalize? Is it have generality? Did you design an experiment in a way that allows you to say that this applies in other settings to other people, in other labs, so on and so forth, so external validity.