Nature of Science

1
Nature of Science

• Goals of Science
• Description
• Explanation
• Prediction
• Control
• Way of knowing the world
• Differs from everyday ways of knowing
• Empiricism
• Not value free as once thought

2
Ethical Concerns

• Protection of Participants
• Informed Consent
• Right to Withdraw
• Avoid Deception

3
Methods Review

• Genetic Studies
• Cross-sectional vs. Longitudinal
• Non-experimental Designs
• Quasi-experimental
• Experimental Designs
• Validity
• Internal
• External

4
Which Method Is Best?
5
Problems in Research

• Bias (misrepresentation of truth)
• Selection Bias
• Treatment Bias
• Remedies?
• Representative Sample
• Random Selection
• Effect Only of Treatment
• Random Assignment
• Ethics

6
Problems with Non-experimental Designs

• Correlation (Treatment Bias)
• Not same as causation
• Question of direction of effect
• Third variable

7
Problems with Experimental Designs

• Generalizability (Selection Bias)
• Cultural differences
• Oversimplified
• Efficacy vs. Effectiveness
• Clinical vs. Statistical Significance

8
When Does Research Reveal Accurate Information?

• Solid research design
• Combination of methods
• Across samples and contexts
• Replication, replication, replication

9
Psychotherapy Research

• Does therapy work?
• How would you know?
• Which therapy is best?
• Dodo bird verdict
• Which therapy works best for
• This disorder
• This client
• Etc.

10
Psychotherapy Research

• Potential Biases
• Sampling and generalizability
• Who is doing the research
• What is being researched (and what is not)
• Statistical vs. Clinical Significance