 naive observer. Literally exactly like it sounds. This is somebody that doesn't know what you're doing. Actually no, they do know what they're doing. Perfect where he's hired. So somebody that is unaware of the purpose of the study that's going on or the phase changes and all that fun stuff, all the details of the study, they don't, we don't want them to know anything. We just want them to count behavior. The reason we don't want them to know anything about what's going on, hypotheses, details of the experiment study, whatever you're doing is that they will tend to do hypothesis guessing and stuff like that and they can just bias their record or their data. We want to reduce bias by keeping them naive. In another context, in another world research methods, we might call this a type of blinding, but in this case we're blinding the observer. So they just don't know what's happening. They can see the behavior but they don't know if it's supposed to go up, go down, they don't know what the goals of the experiment are so they're not going to bias the results.