Which variable changes in the investigation depicted in the drawing?

In the investigation depicted in the drawing, the variable that changes is the independent variable. This is the variable that is deliberately manipulated or changed by the researcher to observe its effect on the dependent variable. The dependent variable, on the other hand, is the variable that is being measured or observed for changes as a result of the manipulation of the independent variable. In this investigation, the independent variable is likely being altered to see how it impacts the dependent variable.