Overview
This lecture covers the importance of scientific methods in psychological research, the pitfalls of intuition and bias, and introduces core research methodologies.
Intuition vs. Scientific Inquiry
- Intuition about human behavior is often unreliable due to hindsight bias and overconfidence.
- Hindsight bias is the tendency to believe, after an event, that you "knew it all along."
- Humans perceive order in random events, leading to false assumptions.
Scientific Method in Psychology
- The scientific method begins by transforming broad questions into operationalized, testable propositions.
- A scientific theory organizes observations and predicts outcomes.
- A hypothesis is a specific, testable prediction that stems from a theory.
- Replication (repeating studies with consistent results) is vital for reliable findings.
Research Methods
- Case Studies: In-depth observation of one individual; good for generating hypotheses but cannot be generalized or replicated.
- Naturalistic Observation: Observing subjects in their natural environment without interference; can describe behavior but not explain it.
- Surveys/Interviews: Collect self-reported data; question wording and sampling bias can affect validity.
- Random sampling ensures all population members have equal chance of participation.
Correlation vs. Causation
- Correlation is when two variables are related but does not prove that one causes the other.
- Outside factors, or confounding variables, can influence apparent correlations.
Experimental Research
- Experiments manipulate an independent variable to observe its effect on a dependent variable.
- Participants are randomly assigned to experimental or control groups to minimize bias.
- Placebos and double-blind procedures help prevent participant and experimenter bias.
- Informed consent is required for experiment participation.
Example Experiment: Caffeine and Problem Solving
- Hypothesis: "Adults given caffeine navigate a maze faster than those not given caffeine."
- Independent variable: caffeine dosage; dependent variable: maze completion speed.
- Use control (placebo), low dose, and high dose groups; analyze results to test hypothesis.
Key Terms & Definitions
- Hindsight Bias — Believing, after an event, that you could have predicted the outcome.
- Operationalize — Define variables in measurable, replicable terms.
- Theory (scientific) — An explanatory framework for observations that predicts future events.
- Hypothesis — A testable prediction derived from a theory.
- Case Study — Detailed analysis of one subject or case.
- Naturalistic Observation — Observing behavior in its natural setting.
- Survey — Research method using questionnaires or interviews to gather data.
- Random Sample — Participants selected so every member has an equal chance to join.
- Correlation — A relationship between two variables; not proof of causation.
- Experiment — Research method that manipulates variables to test cause and effect.
- Independent Variable — The manipulated factor in an experiment.
- Dependent Variable — The measured outcome in an experiment.
- Confounding Variable — An outside factor that could affect the experiment’s results.
- Placebo — An inert substance used as a control in experiments.
- Double Blind — Both participants and experimenters are unaware of group assignments.
Action Items / Next Steps
- Review key research methods and their strengths/weaknesses.
- Practice identifying independent, dependent, and confounding variables in sample experiments.
- Prepare for a quiz on scientific method terminology and experimental design.