PSYC1040 Concise Notes

The Scientific Process and Experimental Design

The Scientific Method

  • Definition: A systematic approach for acquiring knowledge through observation and experimentation.
  • Key Concepts: Differentiation between knowledge from experience, authority, rationalism, empiricism, and science.

Principles of the Scientific Method

  • Objectivity: Evidence must be observable by anyone, avoiding personal bias.
  • Skepticism: Claims must be backed by evidence, evaluated critically.
  • Openness: Transparent reporting of methods for reliability verification.
  • Tentativeness: Scientific knowledge is provisional and subject to revision based on new evidence.
  • Independence: Authority claims must be supported by evidence, not just their status.

Assumptions of Science

  • Nature is Organized: There are general laws explaining natural phenomena.
  • Determinism: Knowledge allows prediction of behavior.
  • Solvable Problems: Science only addresses questions that can be empirically tested.

Goals of Psychology

  1. Describe Behavior: Identify how and when behaviors occur.
  2. Explain Behavior: Seek understanding of the causes of behaviors.
  3. Predict Behavior: Anticipate future behaviors.
  4. Control Behavior: Modify behaviors as needed.

Scientific vs Non-Scientific Theories

  • Theory: A well-structured set of propositions summarizing knowledge.
  • Hypothesis: A specific, testable prediction derived from theories.

Types of Research Methods

  • Basic Research: Knowledge for understanding fundamental principles.
  • Applied Research: Addresses specific problems in practical contexts.
Experimental Design
  • True Randomized Experiments: Allow causality inference through manipulation of independent variables (IVs).
  • Control Groups: Essential for a comparative basis in experiments.
Experimental Variables
  • Independent Variable (IV): The manipulated factor in an experiment.
  • Dependent Variable (DV): The measurement affected by the IV.
  • Confounding Variables: Factors that may interfere with the effect of the IV.
Criteria for Causality
  1. Relationship: Correlation must exist between variables.
  2. Time Order: The cause must precede the effect.
  3. Discount Alternative Causes: Other explanations must be ruled out.

Measurement Scales

  • Nominal: Categorizes without order (e.g. gender).
  • Ordinal: Ranks data without specific intervals (e.g. race results).
  • Interval: Ranks with equal distances between points (e.g. temperature).
  • Ratio: Same as interval but has an absolute zero (e.g. age).

Measurement Issues

  • Reliability: Consistency of measurements over time.
  • Validity: The degree to which a measure reflects the intended construct.