Clinical research is taking place on a promising new drug to treat a heart condition that causes irregular heart beats. In vitro studies have shown the drug works on heart tissue, and animal studies have shown the drug is safe and effective in mice. The clinical trials design is outlined below: The research facility recruited 100 human volunteers that, other than their heart condition, are healthy. The volunteers were divided into two groups. Group 1 is given the medication at 8 a. m. and 8 p. m. daily, and Group 2 is given a placebo at 8 a. m. and 8 p. m. daily . Both groups have an EKG taken twice a day at noon and at 4 p. mto measure the rate and rhythm of their heart. ( Note: An EKG is a test that checks the electrical activity of the heart and heart rate. It shows whether the heart is beating in a regular rhythm or in an irregular rhythm.)

1. List all of the things in this design that are the same for both Group A and Group B:

2. The items you listed in #1 above is the in this experiment because they are kept the same for both groups.

3. What is it that the researchers measure each day at noon and 4 p. m.?

4. The item you listed in #3 above is the variable in this experiment, because that is what the experiment is measuring.

5. What two items are being given to the volunteers?

6. Both of the items you listed above are considered to be "medicine," so what kind of variable is the medication? variable.

7. Which group is the experimental group ?

8. Which group is the control group?

9. Which group would show no change in their heart rhythm and rate

10. Which group would show improvement if the drug is effective ?