1. In the following examples, identify the independent and dependent variable(s):

 a. Two groups of children were given different types of physical fitness programs to determine whether the programs had an effect on their strength.

2. A group of 100 heavy smokers was divided into five groups, and each group participated in a different smoking-cessation program. After 6 months of program participation, the number of cigarettes each participant smoked each day was counted.

3. A university professor was interested in determining the best way to teach introductory psychology and ensure that his students would learn the material.