Research Methods Review: Identification of Independent and Dependent Variables

Research Design Definitions

• Independent Variable ($IV$): The factor, treatment, or stimulus condition that is systematically manipulated, varied, or controlled by an investigator to observe its causal impact on an outcome.
• Dependent Variable ($DV$): The observable response, behavior, or physiological state that is measured by an investigator to determine whether it changes as a function of the independent variable.

Scenario 1: Workplace Satisfaction in Industrial/Organizational Psychology

• Research Problem: An industrial/organizational psychologist tests to see if wearing name tags makes employees happier in their work.
• Subfield of Psychology: Industrial/Organizational Psychology.
• Independent Variable ($IV$): Wearing name tags (manipulated condition: wearing name tags versus not wearing name tags).
• Dependent Variable ($DV$): Employee happiness in their work (measured level of workplace happiness).

Scenario 2: Data Memory and Format in Cognitive Psychology

• Research Problem: Cognitive psychologists are interested in whether a table or a graph makes it easier for people to remember data.
• Subfield of Psychology: Cognitive Psychology.
• Independent Variable ($IV$): Format of data presentation (manipulated factor: table versus graph).
• Dependent Variable ($DV$): Ease of remembering data (measured data recall or memory performance).

Scenario 3: Interpersonal Behavior and Cooperation in Social Psychology

• Research Problem: A social psychologist wants to know whether being polite or rude to people makes them more cooperative.
• Subfield of Psychology: Social Psychology.
• Independent Variable ($IV$): Social demeanor/treatment toward people (manipulated condition: politeness versus rudeness).
• Dependent Variable ($DV$): Level of cooperation (measured cooperativeness of participants).

Scenario 4: Media Violence and Physiological Response in Clinical Psychology

• Research Problem: A clinical psychologist is interested in how heart rate is affected by viewing a violent film as opposed to a nonviolent film.
• Subfield of Psychology: Clinical Psychology.
• Independent Variable ($IV$): Type of film content viewed (manipulated stimulus: violent film versus nonviolent film).
• Dependent Variable ($DV$): Heart rate (physiological rate measurement).