The Scientific Method in Psychology

The Scientific Method: Characteristics and Principles

• Objectivity: Empirical measurements and standardized procedures are used to minimize bias and ensure findings are based on observable data, not subjective interpretations
• Confirmation: Replication of prior research is crucial, either exact replication or replication with extensions to new variables/conditions. Replication is challenged by publication bias and complex studies.
• Self-correction: Research acknowledges the possibility of errors and encourages revision of hypotheses, methods, or interpretations based on new evidence or critiques. Meta-analyses are crucial for synthesizing findings from multiple studies.
• Control: Control is used to isolate the effects of the independent variable, ensuring only that variable differs between experimental conditions. Sophisticated statistical techniques are used to control for extraneous or confounding variables.

The Psychological Experiment: Variables and Relationships

• Independent Variable (IV): The variable manipulated or selected by the researcher to understand its effect on the dependent variable. The presumed cause
• Dependent Variable (DV): The variable measured by the researcher to assess the effect of the independent variable. The presumed effect. Valid and reliable measurements are key.
• Extraneous Variables (EVs): Variables other than the IV that could potentially influence the DV, potentially confounding the results. Controlling for EVs is crucial to determining the true effect of the IV

Formulating and Testing Hypotheses

• Hypotheses: Testable predictions about relationships between variables. Derived from a theory or observation. Directional (predicting a specific direction of the effect) and non-directional (predicting an effect but not the direction) hypotheses exist.
• Types of Statements: Analytic statements are always true and are not useful for research. Contradictory statements are always false and are not useful for research. Synthetic statements can be true or false and are valuable in research.
• Research Strategies: Confirmation strategies aim to confirm hypotheses while disconfirmation strategies aim to disprove them. Inductive reasoning moves from specific to general conclusions, and deductive reasoning moves from general principles to specific predictions.

Controlling Extraneous Variables

• Randomization: Ensures each participant has an equal chance of being assigned to any condition. Reduces the influence of unknown extraneous variables
• Elimination: Removing EVs completely from the study.
• Constancy: Keeping EVs at a consistent value to control for known variables.
• Balancing: Distributing EVs evenly across groups. Requires knowledge of the extraneous variables
• Repeated Measures: Each participant is exposed to all conditions. Accounts for individual differences but can lead to potential order effects
• Counterbalancing: Varying the order of conditions to control for order effects

Participants in Research

• Participant Selection: Choosing participants based on precedent (established types), availability, or research questions.
• Number of Participants: The number needed depends on the similarity (homogeneity) within the sample.

Apparatus and Measurement

• Apparatus: The equipment used to present the IV and measure the DV.
• DV Recording: Accurate and objective recording of the DV is important. Automation can help reduce experimenter bias.

Experimenter and Participant Biases

• Experimenter Effects: Experimenter characteristics and expectations can influence participant responses.
• Participant Effects: Demand characteristics (participants' perception of the study's purpose) and good participant effect (participants trying to conform) influence responses.
• Response Biases: Yea-saying and nay-saying are biases in participant responses

Culture and Research

• Etic: Findings consistent across cultures
• Emic: Findings specific to particular cultures

Facts to Memorize

• Key terms (independent and dependent variables, extraneous variables)
• Research methods (replication, control, randomization)
• Hypothesis types (directional, non-directional)
• Statistical concepts (variability, homogeneity, meta-analyses)
• Bias considerations (experimenter bias, participant bias)