Suppose an instructor wants to study the association between caffeine intake and performance in the long jump. Th e instructor asks her students to suggest ways to collect data to investigate this question. For each of the suggestions, identify:
• Whether the study is an experiment or an observational study
• Whether or not the data will be paired
a. Lara suggests the instructor record everyone’s performance on a long jump and then ask each of them to report their caffeine intake from earlier in the day.
b. Mimi suggests the students be paired by height and then one student in each pair is randomly assigned to caffeine while the other isn’t.
c. Nia suggests all students be given both a caffeine pill and a placebo but the order be randomized. Students’ performances on both these occasions should then be recorded.