 Extraneous variable. I don't know. Some people like to differentiate extraneous variables and concomitant variables and confounding variables. I suppose they are, in a sense. They're all interrelated, right? So an extraneous variable is a variable in the experimental setting that you need to control. That you need to make sure that it's static. It doesn't change because if it changes, it becomes a confounding variable, especially if you didn't change it on purpose. If you changed it on purpose, then it's probably an independent variable and you're confused yet. So anyway, extraneous variable, it's just simply the experimental setting that you need to, like, you need to keep control of to prevent the effects of whatever variable that is on your experiment. So for example, if we were doing an experiment in a lab, you might want to control the noise level. Yes, you do. How about the temperature? Yes, you do. How about the lighting effects? Yes, you do. So those are all extraneous variables that you need to control in order to determine if your independent variable had an effect on your dependent variable.