Overview
This lecture explains how psychological research applies the scientific method, explores major research methods, and covers key concepts like operationalization, bias, and experimentation.
Scientific Method in Psychology
- Research begins with formulating general questions and converting them into measurable, testable propositions—called operationalization.
- A scientific theory explains and organizes many observations and predicts outcomes.
- A hypothesis is a testable prediction derived from a theory.
- Clear definitions and language enable replication, which is vital for reliable research results.
Descriptive Research Methods
- Case Studies: In-depth examination of one individual; useful for framing questions but limited due to lack of replication.
- Naturalistic Observation: Observing behavior in natural environments without interference; describes behavior but cannot explain its causes.
- Surveys and Interviews: Collect data on attitudes and behaviors; question wording and sampling methods can greatly influence results.
- Biased sampling, such as only surveying specific groups, leads to unrepresentative findings; random sampling ensures fairness.
Correlations and Predictive Relationships
- Correlation examines how two behaviors or traits are related but does not prove causation.
- Correlations can predict the possibility of a relationship but cannot establish cause and effect.
Experimental Research
- Experiments test cause and effect by manipulating an independent variable and holding other variables constant.
- Subjects are randomly assigned to experimental and control groups to minimize confounding variables.
- A placebo can be used in control groups, and double-blind procedures prevent bias from researchers and participants.
- Informed consent from participants is ethical and necessary.
Example Experiment: Caffeine and Problem-Solving
- A clear, testable hypothesis: "Adults given caffeine will navigate a maze faster than those not given caffeine."
- Independent variable: caffeine dosage; dependent variable: maze completion speed.
- Subjects randomly assigned to control (placebo), low dose, or high dose groups.
- Results compared to test the hypothesis; clear methods enable replication.
Key Terms & Definitions
- Operationalization — Turning abstract concepts into measurable variables.
- Theory — An explanation organizing observations and predicting outcomes in science.
- Hypothesis — A specific, testable prediction derived from a theory.
- Replication — Repeating a study to verify results.
- Case Study — Detailed analysis of a single individual.
- Naturalistic Observation — Observing subjects in their natural setting.
- Survey — A data collection tool for self-reported attitudes or behaviors.
- Random Sample — Sampling method giving all members equal selection chance.
- Correlation — A measurement of how two variables move together.
- Causation — When one variable directly affects another.
- Independent Variable — The variable manipulated in an experiment.
- Dependent Variable — The outcome measured in an experiment.
- Control Group — Group not exposed to the experimental variable.
- Placebo — An inactive substance or treatment given to a control group.
- Double-Blind Procedure — Neither participants nor researchers know group assignments.
- Confounding Variable — Outside variable that could affect the experiment’s results.
- Informed Consent — Participant agreement after being informed about the experiment.
Action Items / Next Steps
- Review types of research methods and their strengths/limitations.
- Practice identifying independent and dependent variables in sample experiments.
- Understand how to minimize bias and ensure ethical research practices.