Question

1. you want to design an experiment to determine if a new drug has an impact on lowering blood pressure. test subjects with high blood pressure are given a new medication in pill form. the percentage of patients whose blood pressure decreased is measured. what are good positive and negative controls?

Explanation:

To determine good controls for the experiment testing a new drug's effect on lowering blood pressure:

Positive Control:

A positive control is a group that is expected to show a positive result (i.e., a decrease in blood pressure) to ensure the experimental setup is working. For this experiment, a group of test subjects with high blood pressure could be given a known effective blood - pressure - lowering medication (e.g., a commonly prescribed antihypertensive like lisinopril). Since this medication is known to lower blood pressure, if the experiment is working correctly, we should see a decrease in blood pressure in this group. This helps to validate that the method of measuring blood pressure and the overall experimental procedure are capable of detecting a blood - pressure - lowering effect.

Negative Control:

A negative control is a group that is expected to show no effect (no decrease in blood pressure) to account for factors other than the drug that might cause a change. In this case, a group of test subjects with high blood pressure could be given a placebo pill (a pill with no active drug ingredient, like a sugar pill) in the same form as the new medication. Since the placebo has no active ingredient that should lower blood pressure, if the experiment is working correctly, we should not see a significant decrease in blood pressure in this group. This helps to rule out factors such as the placebo effect (where patients feel better or show a change just because they think they are taking a treatment) or other confounding factors related to the experimental procedure (like the act of taking a pill) from influencing the results.

Answer:

• Positive Control: A group of test subjects with high blood pressure given a known effective blood - pressure - lowering medication.
• Negative Control: A group of test subjects with high blood pressure given a placebo pill (with no active drug ingredient) in the same form as the new medication.