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.

IV:

DV:

Two groups of subjects were told they were going to receive electrical 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.
IV:

DV:

One half of the Principles of 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 information.
IV:

DV:

An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.

A dependent variable is the response or measure of results.

I will do the first problem for you.

IV = what they are fed

DV = weight

IV: Breast-feeding and Infant Formula X

DV: Weight of infants

IV: Perceived pain level of electrical shocks

DV: Preference for waiting individually or with a group

IV: Method of instruction (computerized exercises or reviewing text/lecture notes)

DV: Performance on the course information test

IV: The independent variable in the first experiment is breast-feeding and Infant Formula X in underdeveloped countries. It is the variable that the experimenter manipulates or controls.

DV: The dependent variable in the first experiment is the weight of the infants every three days for the first four weeks of life. It is the variable that is measured and expected to be influenced by the independent variable.

IV: The independent variable in the second experiment is the information given to the two groups about the type of shocks they would receive. It is the variable that the experimenter manipulates or controls.

DV: The dependent variable in the second experiment is whether the subjects choose to wait individually or with a group while the shock machinery is being set up. It is the variable that is measured and expected to be influenced by the independent variable.

IV: The independent variable in the third experiment is the type of instruction received by the Principles of Psychology students. It is the variable that the experimenter manipulates or controls.

DV: The dependent variable in the third experiment is the performance of the students on the course information test. It is the variable that is measured and expected to be influenced by the independent variable.

For each scenario given, let's determine the Independent Variable (IV) and Dependent Variable (DV):

Scenario 1:
IV: Breast-feeding and Infant Formula X (the experimenter is interested in studying the relationship between these two variables)
DV: Weight of the infants every three days for the first four weeks of life (the variable being measured to determine any potential effects of breast-feeding and Infant Formula X)

Scenario 2:
IV: Description of the shocks (one group is told the shocks would be relatively painful, while the other group is told the shocks would be mild and produce a "tickling sensation")
DV: Choice of waiting individually or with a group while the shock machinery is being set up (the variable being measured to determine any potential effects of the different descriptions of the shocks)

Scenario 3:
IV: Type of instruction (one half of the students completed computerized instruction exercises, while the other half reviewed the text and lecture notes)
DV: Performance on the course information test (the variable being measured to determine any potential effects of the different types of instruction)