Psychology Cram Packet Notes

Unit Zero - Research and Design

Basic Vocabulary

  • Hypothesis: A tentative explanation that must be falsifiable, meaning it can be supported or rejected.
  • Operational Definition: A clear, precise, and quantifiable definition of variables. It allows for replication and collection of reliable data.
  • Qualitative Data: Descriptive data (e.g., eye color).
  • Quantitative Data: Numerical data, which is ideal and necessary for statistics.
  • Population: Everyone the research could apply to.
  • Sample: The specific people (or person) chosen for the study.

Research Designs

Correlation

  • Identifies the relationship between two variables.
  • Advantage: Useful when experiments are unethical.
  • Disadvantage: Correlation does not equal causation.
    • Directionality Problem: It's unclear which direction the correlation goes (e.g., does depression cause low self-esteem, or does low self-esteem cause depression, or is there a third variable?).
    • 3rd Variable Problem: A different variable is responsible for the relationship (e.g., ice cream sales and murder rates).
    • Positive Correlation: Variables increase and decrease together.
    • Negative Correlation: As one variable increases, the other decreases.
    • Strength of Correlation: The stronger the number, the stronger the relationship, regardless of the positive or negative sign. Cannot be less than or greater than 1.
    • Stronger relationships = tighter clusters on a graph.

Experiments

  • Purposefully manipulate variables to determine cause and effect.
  • Advantage: Only type that establishes cause and effect.
  • Disadvantage: Can be unethical or too artificial.
Vocab Unique to Experiments:
  • Independent Variable: Purposely altered by the researcher to look for an effect.
    • Experimental Group: Receives the treatment (part of the IV); can have multiple experimental groups.
    • Control Group: Receives a placebo or baseline treatment (part of the IV); can only have one control group.
  • Dependent Variable: The variable that is measured and is dependent on the independent variable.
  • Placebo Effect: Any observed effect on behavior that is caused by the placebo. It shows the effectiveness of the experimental treatment, and is usually fixed with blinded studies.
  • Double-Blind: An experiment where neither the participant nor the experimenter knows which condition people are assigned to (e.g., drug studies).
  • Single-Blind: Only the participant is blind, used if the experimenter can't be blind (e.g., gender, age).
  • Confound: Error or flaw in the study that is accidentally introduced (also called a confounding variable).
  • Random Assignment: Assigns participants to either the control or experimental group at random, increasing the chance of equal representation among groups. Allows you to infer cause and effect.

Other Study Types

  • Naturalistic Observation: Observe people in their natural settings.
    • Advantage: Real-world validity.
    • Disadvantage: No cause and effect can be determined.
  • Case Study: Studies one person (usually) in great detail.
    • Advantage: Collect lots of information.
    • Disadvantage: No cause and effect can be determined.
  • Meta-Analysis: Combines multiple studies to increase sample size and examine effect sizes.

Statistics

Descriptive Stats

  • Show the shape of the data.
    • Measures of Central Tendency:
      • Mean: Average (use in normal distribution).
      • Median: Middle number (use in skewed distribution).
      • Mode: Occurs most often.
        • Bimodal: Has two modes, usually indicating good and bad scores.
    • Skews: Created by outliers.
      • In negative skew, the mean is to the left (negative side), and the mode is to the right.
      • In positive skew, the mean is to the right.
    • Measure of Variation
      • Range - Distance between the smallest and biggest #
      • Standard deviation - avg. amount the scores are spread from the mean (bigger #=more spread)

Inferential Statistics

  • Establishes significance (meaningfulness).
    • Statistical Significance: Results not due to chance; the experimental manipulation caused the difference in means.
      • p < .05 (p-value less than 0.05) indicates statistical significance; smaller is better.
    • Effect Size: Data has practical significance; bigger is better.

Ethical Guidelines (IRB Approval Needed for People)

  • Confidentiality: Names kept secret.
  • Informed Consent: Participants must agree to be part of the study.
  • Informed Assent: Minors AND their parents must agree.
  • Debriefing: Participants must be told the true purpose of the study (done after for deception).
  • Deception: Must be warranted.
  • No Harm: Mental/physical.

Additional Vocabulary

  • Surveys: Usually turned into correlations.
  • Subject to self-report bias
    • Social Desirability: People lie to look good.
    • Wording Effects: How you frame the question can impact your answers.
  • Random Sample (Selection): Method for choosing participants for the study. Everyone has a chance to take part and increases generalizability.
    DO NOT MIX Random Sample and Random Assignment. Sample = Generalize. Assignment = Cause/Effect
  • Representative Sample: Sample mimics the general population (ethnic, gender, age).
  • Convenience Sample: Select participants based on availability. Less representative and less generalizable this way.
  • Sampling Bias: Sample isn't representative due to convenience sampling.
  • Cultural Norms: Behaviors of a particular group can influence research results.
  • Experimenter Bias/Participant Bias: Experimenter/participant expectations influence the outcome.
  • Cognitive Bias: Bias in thinking/judgment
    • Confirmation Bias: Find information that supports preexisting beliefs.
    • Hindsight Bias: "I knew it all along."
    • Overconfidence: Overestimate our knowledge/abilities.
    • Hawthorne Effect: People change behavior when watched.
  • Research needs peer review and adequate sample sizes.