4 According to a commercial, drinking water that has been blessed by Bill Nye the Science Guy improves your test scores. You think this is complete nonsense and want to disprove it. So you set up an experiment.
4a Would this be an observational or an empirical study?
4b To test it, for a total of 10 weeks, you take one test every week. Alternating weeks, you will drink regular water (control) and blessed water (treatment). How many replicas will you have?
4c What would be your null-hypothesis?
4d What would be your alternative hypothesis?
4e Name 3 possible confounding factors.
4f What is your independent variable?
4g Wat is your dependent variable?
4hs You set your a-level as always at 0.05, and do a statistical analysis to see if there is a difference in test scores between the two groups. The statistical analysis result is p=0.06 Is there a significant difference in test scores? Yes / No / Donât know
4i Based on the statistical analysis outcomes, does drinking blessed water improve test results? Yes / No / Donât know
4j 10 points A placebo effect is an improvement in a personâs perceived health from taking a non-active ingredient, presumably because of the belief that they are receiving a treatment helps that person to feel better. Your mind is a powerful thing and certainly can influence your health in real ways, so a placebo effect would include real improvements that come from âmind over matterâ as well as simple changes in perception. How can you avoid the placebo effect in this study?
