Overview
This lecture introduces the scientific method in psychology and explains how research methods help avoid common human biases and errors in understanding behavior.
The Pitfalls of Intuition
- Intuition is often misleading and can reinforce itself through hindsight bias ("I-knew-it-all-along" phenomenon).
- Overconfidence can cause us to believe incorrect assumptions about behavior.
- Humans perceive patterns in random events, leading to false conclusions.
The Scientific Method in Psychology
- Scientific research starts with forming general questions and turning them into measurable, testable propositions (operationalizing).
- A scientific theory explains, organizes observations, and predicts outcomes.
- Hypotheses are testable predictions derived from theories.
- Precise definitions ensure experiments can be replicated by others.
Research Methods in Psychology
- Case Studies: In-depth examination of one individual; good for generating questions but not for generalizing results.
- Naturalistic Observation: Observing subjects in their natural environments; describes behavior but does not explain it.
- Surveys and Interviews: Collect self-reported data; question phrasing and sampling methods affect results.
- Random sampling is necessary for representative results.
Correlation vs. Causation
- Correlations show relationships between variables but cannot prove cause and effect.
- Other factors (confounding variables) may explain observed relationships.
Experimental Method
- Experiments manipulate an independent variable to observe its effect on a dependent variable, while controlling other variables.
- Participants are randomly assigned to experimental or control groups to avoid confounding variables.
- Placebos and double-blind procedures help prevent bias.
- Informed consent from participants is required for ethical research.
Example Experiment: Caffeine and Problem-solving
- Hypothesis: Adults given caffeine will navigate a maze faster than those without caffeine.
- Control group receives placebo (decaf); experimental groups receive different doses of caffeine.
- Random assignment and clear, replicable procedures are essential.
Key Terms & Definitions
- Hindsight Bias — the tendency to believe, after an event, that you predicted the outcome all along.
- Operationalizing — defining abstract concepts in measurable terms for research.
- Theory — an explanation that organizes and predicts relationships among variables.
- Hypothesis — a testable prediction derived from a theory.
- Case Study — in-depth analysis of a single individual or case.
- Naturalistic Observation — watching subjects in their natural setting without interference.
- Survey — a research method that collects self-reported data.
- Random Sample — a subset of a population where every member has an equal chance of being selected.
- Correlation — a measure of how two variables relate, not implying causation.
- Confounding Variable — an outside factor that may affect experiment results.
- Double Blind — neither subjects nor researchers know who is in the experimental or control group.
- Placebo — an inert substance given to a control group for comparison.
Action Items / Next Steps
- Review definitions of research methods and biases.
- Practice distinguishing between correlation and causation in sample scenarios.
- Prepare for next class by reading about ethical guidelines in psychological research.