Independent and Dependent Variables
Identifying Dependent and Independent Variables
Instructions: For each of the following research designs, identify the dependent and independent variables.
1. To investigate the effects of exercise on mathematical problem-solving ability, a researcher assigned subjects to one of two groups. One group did 50 jumping jacks and the other group did 200. After exercising, both groups did a set of math problems.
2. A researcher hypothesized that talking to plants enhances their growth. To test her hypothesis, she gave two plants the same amount of food, water, and sunlight, but she talked to one plant and not the other.
3. In order to study the relationship between neonatal exercise and motor development, a professor randomly assigns 50 one-week-old infants to Group A or Group B. The 25 infants in group A participate in a daily 15-minute exercise program. The infants in Group B are not exposed to anything beyond their normal daily activities. Twice a month for an entire year, subjects from both groups are given a motor-skills test.
4. An experimenter wants to study the relationship between breast-feeding and Infant Formula X in underdeveloped countries. She randomly assigns 300 infants to Group A or B and weighs the infants every three days for the first four weeks of life.
5. Two groups of subjects were told they were going to receive electric shocks as part of a learning experiment. One group was told that the shocks would be relatively painful. The other group was told that the shocks would be mild and produce a “tickling sensation.” The subjects were then asked if they wished to wait individually or with a group while the shock machinery was being set up.
6. One half of the General Psychology students completed computerized instruction exercises. The remaining half spent an equal amount of time reviewing the text and lecture notes. Both groups were tested on the course
Instructions: For each of the following research designs, identify the dependent and independent variables.
1. To investigate the effects of exercise on mathematical problem-solving ability, a researcher assigned subjects to one of two groups. One group did 50 jumping jacks and the other group did 200. After exercising, both groups did a set of math problems.
2. A researcher hypothesized that talking to plants enhances their growth. To test her hypothesis, she gave two plants the same amount of food, water, and sunlight, but she talked to one plant and not the other.
3. In order to study the relationship between neonatal exercise and motor development, a professor randomly assigns 50 one-week-old infants to Group A or Group B. The 25 infants in group A participate in a daily 15-minute exercise program. The infants in Group B are not exposed to anything beyond their normal daily activities. Twice a month for an entire year, subjects from both groups are given a motor-skills test.
4. An experimenter wants to study the relationship between breast-feeding and Infant Formula X in underdeveloped countries. She randomly assigns 300 infants to Group A or B and weighs the infants every three days for the first four weeks of life.
5. Two groups of subjects were told they were going to receive electric shocks as part of a learning experiment. One group was told that the shocks would be relatively painful. The other group was told that the shocks would be mild and produce a “tickling sensation.” The subjects were then asked if they wished to wait individually or with a group while the shock machinery was being set up.
6. One half of the General Psychology students completed computerized instruction exercises. The remaining half spent an equal amount of time reviewing the text and lecture notes. Both groups were tested on the course