Lecture Notes: Scientific Methods in Psychology

Overview

• Purpose of Psychology as a Science
  • Explain psychological phenomena: thoughts, emotions, behaviors.
  • Use systematic methods to observe behavior and make inferences.
  • Develop theories to explain these phenomena.

Scientific Thinking in Psychological Science

• Definition of Science
  • Knowledge based on carefully observed and replicable data.
  • Differs from layman's theories by its reliance on systematic observation.

Research Process in Psychological Science

• Stages of Research
  1. Formulation of Hypothesis
     • Based on observations or general statements.
     • Example: Children imitating behaviors seen in video games.
  2. Hypothesis Testing
     • Requires systematic methods.
     • Example Study: Divide children into groups with violent vs. non-violent games and compare aggression.
  3. Measurement and Observation
     • Clear definitions and rules are crucial.
     • Difficult phenomena like aggressive behavior need precise measurement for conclusive results.
  4. Interpreting Results
     • Results contradicting the hypothesis lead to abandonment/modification.
     • Supportive results increase confidence but require consideration of other hypotheses.
  5. Replicability
     • Important for confirming research results.
     • Methods and procedures must be detailed for replication.
     • Misrepresentation risks credibility loss.

Evaluations and Indicators of Scientific Theory

• Indicators of a Good Theory
  1. Replicability
     • Supported by results that can be consistently replicated.
  2. Falsifiability
     • Theory must be clear enough to be proven false if evidence arises.
  3. Burden of Proof
     • Proponents must provide empirical evidence supporting the theory.
  4. Principle of Parsimony (Occam's Razor)
     • Simplicity in assumptions is key.
     • Prefer established theories with few assumptions.

Meta-Analysis

• Purpose and Use
  • Analyzes results of multiple studies to treat them as one large study.
  • Helps determine replicability of effects.
  • Crucial for evaluating results from studies with small participant numbers.

Psychology as a Science

• Status Evaluation
  • Good theories help deduce and explain phenomena based on replicable data.
  • Emphasize simplicity and accurate predictions.
• Differences from Pseudoscience
  • Based on data that supports multiple hypotheses.
  • Use indicators like replicability and falsifiability to evaluate theories.