Independent and Dependent Variables

I am struggling with being able to identify independent and dependent variables. For example, in an experiment, a group of students are handed a fidget spinner as they read a book page and another group was not given a fidget spinner. All students were given the same questions to answer. Their respective, correct responses were recorded. Is the independent variable the fidget spinner? And is the dependent variable the number of correct responses?


TS Contributor
The independent variable is the suspected or theorized causal factor under investigation, often called a treatment or factor. The treatment is independent and can be varied as is feasible and desired by the experimenter.
The dependent variable is the observed effect, usually called the response. The response is dependent upon the level of a causal factor.


Not a robit
Just to clarify and confuse things:

Exposure -> Outcome

IV -> DV

So there is directionality. DV can impact an IV, but it would be a series and the subsequent IV would be a new one.

IV_t -> DV_t -> IV_t+1 -> DV_t+1

t = time

Drug -> Outcome -> Change Drug Dose -> New Outcome -> …