Research Methods in Psychology

Research Methods

• Correlational Research: Examines the relationship between variables, observing natural occurrences without manipulation.
  • Identifies associations between variables.
  • Cannot establish causality.
  • Uses observational, survey, and archival data.
  • Advantages: Useful for large datasets and when manipulation is not possible.
  • Limitations: Cannot infer causation; confounding variables may exist.
• Experimental Research: Establishes causality by manipulating variables and controlling for confounding factors.
  • Employs controlled and randomized designs.
  • Advantages: Provides strong evidence for cause-and-effect.
  • Limitations: May lack generalizability and present ethical challenges.

Features of an Experiment

• Independent Variable (IV): The factor actively manipulated by the researcher to observe its effect on the dependent variable.
  • Considered the "cause" in the cause-and-effect relationship.
  • Requires at least two levels or conditions to allow for comparison.
  • Levels can be manipulated (actively changed by the researcher) or subject variables (pre-existing participant traits).
• Dependent Variable (DV): The outcome or response being measured in an experiment.
• Extraneous Variables: Factors other than the IV that could influence the DV.
  • Must be controlled to avoid confounding, which occurs when an extraneous variable changes systematically along with the IV.
  • Leads to internal validity, meaning alternative explanations for results are ruled out.
• Internal Validity: Focuses on establishing a cause-and-effect relationship within the study.
  • Ensures changes in the DV are due to the IV, not other influences.
  • Threats include confounding variables, selection bias, maturation, history, and demand characteristics.
• External Validity: Focuses on generalizing research findings to broader contexts outside the study.
  • Concerns whether results apply to other populations, settings, or times.
  • Threats include non-representative samples, artificial settings, and limitations in ecological or population validity.

Pre-Post Studies

• Structure: Measure DV before treatment (pretest), apply IV (treatment), then measure DV again (posttest).
• Steps to Conduct:
  • Identify the research question and define the IV and DV.
  • Ensure pre-test conditions don't influence post-test conditions.

Between-Subjects Designs

• Used when IV is a subject variable (e.g., extroversion, marital status).
• Employs random assignment (distributing individual factors evenly across groups) and matching (creating comparable groups on a matching variable).

Within-Subjects Designs

• Advantages: Fewer participants needed, no problems with equivalent groups, increased statistical power.
• Disadvantages: Practice effects, fatigue effects, and carryover effects (impact of previous condition on the current one).

Single-Factor Designs

• Focus on one independent variable (factor) and examine its effect on a dependent variable.
• Vocabulary:
  • Factor: The independent variable being tested.
  • Level: The different variations or states of the factor being investigated.

Correlational Research

• Examines the relationship between two or more variables without manipulation.
• Key Points:
  • Identifies statistical relationships between variables.
  • Uses correlation coefficient to measure relationship strength and direction (-1 to +1).
  • Does not imply causation.

Explore the fundamentals of research methods used in psychology, including correlational and experimental research designs. Understand the advantages and limitations of each type, and learn about key concepts such as independent variables and causality. This quiz will help you grasp the essential components of conducting psychological research.