Dr. Stein's hypothesis is that excess sugar causes hyperactivity. He is interested in doing research. Which research method would be the best to use?

The best research method to use for the research of hyperactivity,  would be dependent-independent variable experiment.

The given problem is based on the effect of sugar on hyperactivity. Hyper activity refers to the increased movement, impulse actions and a shorter attention span.

Thus, we can conclude that the best research method to use,  would be - dependent-independent variable experiment.

Learn more about the hyperactivity here:

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The correct answer would be - dependent independent variable experiment.

Explanation:

Dr. Stein hypothesized that excess sugar causes hyperactivity, so sugar treatment /no sugar treatment would be independent variable. By giving some children sugar and others a sugar cookies he can manipulate the independent variable.

Similarly , the dependent variable is the result or outcome of independent variable, or what Dr. Stein hypothesize to be the result of excess sugar . In this sugar experiment, then, the dependent variable is the children's hyper activity level.

Thus, the correct answer would be - dependent independent variable experiment.