Identifying the Dependent and Independent Variables
1. Independent variable is a factor that is manipulated in an experiment. The experimenter controls whether or
not subjects are exposed to the independent variable.
2. Dependent variable is measured to determine if the manipulation of the independent variable had any effect.
To identify the dependent variable ask yourself, “What is actually being measured in the experiment?”
For example, to test a hypothesis that eating carrots improves vision, the experimenter would manipulate
whether or not subjects ate carrots. Thus, eating carrots is the independent variable. Each subject’s vision would
be tested to see if carrot eating had any effect. Thus, vision is the dependent variable. The subjects assigned to
eat carrots are in the experimental group, whereas subjects not eating carrots are in the control group.
Identify the independent variable, dependent variable, experimental and control groups YOU MUST ALSO
identify the Steps in the scientific method in the following studies.
1. A group of college students were given a short course in speed-reading. The instructor was curious if a
monetary incentive would influence performance on a reading test taken at the end of the course. Half the
students were offered $5 for obtaining a certain level of performance on the test, the other half were not offered
money.
Independent variable: Dependent variable:
Experimental group: Control group:
Scientific Method:
1. 5.
2. 6.
3. 7.
4.
2. A social psychologist thinks that people are more likely to conform to a large crowd than to a single person.
To test this hypothesis, the social psychologist had either one person or five persons stand on a busy walking
path on campus and look up. The psychologist stood nearby and counted the number of people passing by who
also looked up.
Independent variable: Dependent variable:
Experimental group: Control group:
Scientific Method:
1. 5.
2. 6.
3. 7.
4.
