Answer:
quantitative
Step-by-step explanation:
Dr Baumgartner is using a quantitative approach since he is measuring the amount of time that children spend per day in the activities:
playing video games, watching TV, and studying.
He most likely is going to analyze the relationship between the time spent in that activity in terms of variables. He may also graph according to the time spent and the variable he seeks to relate.
In general quantitative approaches have a clear and identifiable variable that can be measured and results in key findings on the research.