Answer:
Independent variable: method of teaching.
Dependent variable: summer sessions.
confound variable: improvement.
Explanation:
Independent variable is described as a variable that is being manipulated and changed in order to see its effect on the dependent variable. The dependent variable is directly affected by the independent variable.
The dependent variable is described as a variable that is being tested by an experimenter in particular research or experiment.
Confound variable is determined as a "third variable" in an experiment which is responsible for examining an already existing "cause-and-effect" relationship.