Variable Review
Independent (IV) v. Dependent (DV)
Examples of IVs and DVs
- Gender and hiring decision
- Psychological Stress and Blood pressure
- Defendant attractiveness and sentencing
- Effects of Exercise on Health
Notes:
- Last Class I mentioned Environmental Variables and Subject Variables – these are not crucial for our purposes in this class, just note that these are distinctions of types of Independent Variables.
- Term independent variable has assumed different meanings in various areas of behavioral sciences. Some investigators restrict the definition to a variable that is experimentally manipulated in the context of an experiment.
- We adopt a more general definition of independent variable as any variable that is presumed to influence a second variable. According to this definition, no necessary for variable to be experimentally manipulated in order to be an independent variable.
- Distinction between IV and DV parallels cause-and-effect thinking, w/the IV being the cause and DV being effect
- Suppose an investigator is interested in the relationship between two variables: the effect of information about gender of a job applicant on hiring decisions made by personnel managers. An experiment might be designed in which 50 personnel managers are provided with descriptions of a job applicant and asked whether they would hire the applicant. The applicant is described to all 50 managers in the same way on several pertinent dimensions. The only difference is that 25 of the managers are told that the applicant is a woman, and the other 25 managers are told that the applicant is a man. Each manager indicates his or her hiring decision. In this experiment, gender of the applicant is the independent variable and the hiring decision is the dependent variable.
- Hiring decision is DV because “depends” on information about the gender of the applicant
- Gender is IV because thought to influence the DV and does not depend on other variable
