In an experiment, the variable thought to cause the change is the:

1. An experiment tries to establish that one thing changes another. 2. When one variable causes change in another, we call the first variable the explanatory variable. 3. The different values of the explanatory variable are called treatments. 4. The variable being measured for change is the response variable instead. _Source: OpenStax Introductory Statistics 2e (CC BY 4.0), Ch 1 'Sampling and Data', sections 1.1-1.4_