A student observes that she's always sleepy shortly after eating lunch, and she wants to be able to pay better attention in her mid-afternoon class. She tried doing 10 jumping jacks just before the class, but still felt sleepy around the middle of the class. The next day, she tried sipping water throughout the class and found that she could pay attention until the end of the class. The student now brings a water bottle to class. Identify how this student applied the scientific method to solve her problem.