In a controlled experiment in which all the variables remain constant including the one being tested is called?

In a controlled experiment, when all variables remain constant except for the one being tested, it is referred to as a "controlled variable" or "constant variable." This design ensures that any observed effects can be attributed solely to the manipulation of the independent variable, allowing for valid conclusions about its impact. The goal is to isolate the relationship between the independent and dependent variables while minimizing the influence of external factors.