Rick and James want to research the issue of hand washing at their school. They decide to research whether or not placing a poster in the bathroom reminding students to wash their hands has any effect on hand washing. They identify two bathroom locations. They put posters in one bathroom in the facility but do not put the poster in another bathroom. Then they observe and record how many visitors wash their hands in each location. What type of research most accurately describes their project?

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case study

field experiment

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