The intent of this lesson is to introduce young scientists to the steps of the scientific method. To this end, they consider the question, "Which brand of battery lasts longest?" In this case, the experiment is carried out as a class, assigning responsible class members to take the flashlights home, keep them burning, and note when they quit. First of all, brand comparison experiments are not scientific in nature. Secondly, there are too many uncontrolled variables that could affect the outcome.