Psychology Exam Notes

Nature vs Nurture

  • Nature vs nurture explores the influence of genetics (nature) and environment (nurture) on human behavior and characteristics.
  • The debate is largely resolved, acknowledging that development involves inherited genetic instructions interacting with environmental factors.
  • Twin studies are used to determine the roles of genes and environment by studying identical and fraternal twins.

Research Methods

  • Research methods are used to collect data on a specific topic.
  • Psychologists use empirical research that involves systematic observations and experiments.
  • Steps in conducting psychological research:
    1. Identify the research topic.
    2. Formulate a testable hypothesis.
    3. Design the research considering ethical standards.
    4. Collect the data.
    5. Analyze the data.
    6. Interpret and evaluate the results.
    7. Report the research and findings.

Research Question and Aim

  • The research question identifies the specific topic of interest.
  • The research aim states what the research intends to find out.
    • Example: 'To investigate the effects of revision on test scores.'

Formulating a Hypothesis

  • A research hypothesis is a testable prediction of the relationship between variables.
  • It includes:
    • A specific prediction
    • Population
    • Independent variable (IV) with 2 levels
    • Dependent variable (DV)

Variables

  • Independent Variable (IV): The variable manipulated by the researcher.
  • Dependent Variable (DV): The variable used to measure the effects of the IV.
  • Experimental Group: Exposed to the IV.
  • Control Group: Not exposed to the IV; used as a baseline.
  • Extraneous Variables: Other variables that may influence the DV.
  • Confounding Variables: Variables with unwanted effects on DV, confused with IV.

Reliability and Validity

  • Reliability: Consistency of measurements.
  • Validity: Accuracy of measurements.

Target Population and Sample

  • Target Population: A group with specific characteristics relevant to the research.
  • Sample: A subgroup representing the population.
  • Sampling Methods:
    • Convenience sample
    • Random sample
    • Stratified sample
    • Random stratified sample

Allocating Participants to Groups

  • Between Groups: Different groups are subjected to different conditions.
    • Control group (no condition applied)
    • Experimental group
  • Within Groups: The same participants are used in both experimental and control groups.

Non-Experimental Designs

  • Include correlational studies, case studies, longitudinal and cross-sectional studies, surveys, and interviews.

Correlational Studies

  • Examine the relationship between two variables.
  • Can test the reliability of a survey using test-retest methods.

Case Studies

  • Focus on one individual or a small group, studied through various methods.
    • Advantages: detailed insights, useful when few participants are available.
    • Disadvantages: limited generalizability, potential for bias.
  • Data can be:
    • Subjective (from interpretations)
    • Objective (based on facts)

Longitudinal vs. Cross-Sectional Studies

  • Longitudinal: Observations over a period with the same subjects.
    • Advantages: identifies changes and patterns.
    • Disadvantages: costly, time-consuming, participant attrition.
  • Cross-Sectional: Measures outcomes and exposures simultaneously in different age groups.
    • Advantages: fast and inexpensive.
    • Disadvantages: prone to biases, hard to determine causal relationships.

Evidence-Based Conclusions

  • Conclusions should be based on statistically significant results.
  • Avoid stating research "proves"; instead, use "supports" or "fails to support".

Sources of Error

  • Individual participant differences
  • Non-standardized instructions and procedures
  • Order effects
  • Experimenter effects
  • Placebo effects
  • Cohort Effects

Addressing Sources of Error

  • Individual participant differences: Use stratified sampling methods or matched participants.
  • Non-standardized instructions: Standardize instructions with a script.
  • Experimenter effects: Use standardized procedures and peer observation.
  • Order effects: Alternate the order of conditions or complete conditions on different days.
  • Placebo effects: Deception where participants do not know the true purpose of the study.
  • Cohort Effects: Incorporate methods of both cross- sectional and longitudinal studies

Descriptive Statistics

  • Summarize, organize, and describe raw data.
  • Cannot establish cause-and-effect relationships alone.
  • Common forms include percentages, graphs, tables, and measures of central tendency.

Measures of Central Tendency

  • Mode: most frequent number.
  • Median: middle number of ordered scores; less affected by outliers.
  • Mean: average; easy to compute but sensitive to outliers.

Displaying Quantitative Data

  • Tables: Include totals, percentages, measures of central tendency.
  • Bar graphs: Represent statistics and differences between groups.
  • Histograms: Represent continuous statistics.