Overview
This lecture reviews various psychological research methods, their strengths and weaknesses, and compares approaches like case studies, observation, surveys, archival research, and longitudinal vs. cross-sectional designs.
Major Research Methods in Psychology
- Psychologists use methods including observation, surveys, archival research, and experiments to understand behavior and cognitive processes.
- Each method has unique strengths and weaknesses and fits specific research questions.
- Observational, survey, and archival methods are correlational and cannot establish causation.
- Experiments provide control and can test cause-and-effect, but often occur in artificial settings and may have ethical limitations.
Case Studies (Clinical Studies)
- Focus on one or a few individuals, providing rich and detailed information, especially on rare phenomena.
- Limited generalizability due to unique characteristics of individuals studied.
Naturalistic Observation
- Involves observing behavior in its natural context without interference.
- Offers high ecological validity and realism, but is difficult to set up, control, and is time-consuming.
- Observer bias is a risk; clear criteria and multiple observers improve reliability.
Surveys
- Collect data from large samples using questionnaires or interviews.
- Allow generalization to populations if samples are diverse and large.
- Provide limited depth per participant and may be affected by inaccurate self-reports.
- Central tendency measures (mean, median, mode) summarize survey data; mean is sensitive to outliers.
Archival Research
- Uses existing records or data sets to answer research questions.
- Less time and cost investment, but researchers have no control over data quality or consistency.
Longitudinal vs. Cross-Sectional Research
- Longitudinal studies test the same individuals repeatedly over time, ideal for studying change but require substantial time and resources.
- Cross-sectional studies compare different population segments at one point, quicker but may reflect generational differences unrelated to age.
- Longitudinal studies face high attrition rates, which may affect sample representation.
Key Terms & Definitions
- Generalizing — applying findings from a study to the broader population.
- Ecological Validity — the extent to which research findings can be generalized to real-life settings.
- Observer Bias — tendency for observers to influence or skew observations to fit their expectations.
- Inter-rater Reliability — the degree of agreement among independent observers.
- Archival Research — analysis of pre-existing data or records.
- Longitudinal Research — repeated measurements from the same individuals over an extended period.
- Cross-Sectional Research — compares different groups at one time to infer change over time.
- Attrition Rates — reduction in participants over time in longitudinal studies.
Action Items / Next Steps
- Review examples of research methods and their applications.
- Understand the limitations of correlational studies versus experiments.
- Prepare for homework or further readings on experimental research methods.