Psychological Research Study Guide

1. Core Definitions & Scientific Method

  • Psychology: A sociobiological science using controlled techniques and systematic, orderly observation to collect data and answer questions.

  • The Scientific Method Steps:

    1. Ask a Question: Identify a problem from observed phenomena or previous research (e.g., Why are 40% of American adults obese?).

    2. Form a Hypothesis: Translate broad theories into testable predictions.

    3. Collect Data: Select a research design and gather evidence.

    4. Analyze the Results: Process data to evaluate patterns.

    5. Draw Conclusions: Determine if data supports or refutes the hypothesis.

Theory vs. Hypothesis Hierarchy

  • Theory: Broad, vague ideas too general to be directly verified (e.g., Obesity is caused by the American diet).

  • Hypothesis: A testable form of a theory (e.g., Obesity results from high sugar consumption).

  • Operationalized Hypothesis: A highly specific, concrete translation of a hypothesis into measurable terms.

2. Overview of Research Methods

  • Archival Research: Analyzing pre-existing records or data sets.

  • Survey Research: Collecting self-reported data from questionnaires or interviews.

  • Naturalistic Observation: Observing subjects in their natural environment without intervention.

  • Ethnography: Descriptive research where researchers act as participant-observers.

  • Case Study: In-depth examination of a single individual or small group.

  • Correlational Research: Examining relationships between variables without manipulation.

  • Experimental Research: Manipulating variables in controlled conditions to establish cause-and-effect.

3. Correlational Research

  • Definition: Identifies whether an association or relationship exists between two factors or variables.

  • Correlation Coefficient: A mathematical score ranging from -1.0 to +1.0 representing strength and direction:

    • +1.0 (Perfect Positive): Variables move in the same direction (e.g., as salary increases, job satisfaction increases).

    • -1.0 (Perfect Negative): Variables move in opposite directions (e.g., as overtime hours increase, sleep hours decrease).

    • 0 (No Relationship): Variables show no predictable association.

  • CRITICAL RULE: Correlation DOES NOT equal Causation. Finding an association proves nothing about cause-and-effect. Third variables or reverse relationships may account for the connection.

4. Experimental Research

  • Purpose: Designed specifically to discover causal relationships (cause and effect).

  • Core Variables:

    • Independent Variable (IV): The factor directly manipulated by the researcher (e.g., violent vs. non-violent movie exposure).

    • Dependent Variable (DV): The factor measured to see if it changes due to the IV (e.g., level of aggressive behavior).

  • Essential Safeguard: Random Assignment is used to assign subjects to either the Experimental (Treatment) Group or the Control Group to eliminate confounding differences between groups.

5. Threats to Validity & Research Bias

  • Experimental Bias: Factors distorting how the IV influences the DV.

    • Experimenter Expectations: Unintentional signals or behaviors by the researcher that influence participant actions.

    • Participant Expectations: Participants altering behavior to align with what they think the study requires.

  • Hawthorne Effect: The tendency of participants to increase productivity or performance simply because they know they are being observed.

6. Ethics in Psychological Research

  • Primary Rule: Participant rights, welfare, and safety always come first before research goals.

  • Harm Prevention: Subjects must be protected from physical and psychological harm.

  • Informed Consent: Required before participation:

    • Participants over age 7 must voluntarily assent.

    • Participants under age 18 require additional consent from a parent or guardian.