The independent variable is: TV on / TV off . It can only be changed by the psychologist who is running the experiment.
If there was a dependent variable, then it was the students' comprehension of the material they studied. The purpose of the experiment was to determine whether It actually depended on the independent variable or not. ( I'll bet it did. )
In the study, the independent variable is the study condition (TV on vs. TV off), while the dependent variable is the students' performance on the comprehension test. The experiment aims to understand how these conditions affect test results. Analyzing the differences in scores will reveal the impact of the studying environment on comprehension.
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