The Scientific Method

1. The Scientific Method

2. Write your answers to the following on a sheet of paper. True or False • Science is a collection of facts • Hard sciences are more rigorous and scientific than soft sciences. • Scientific ideas are absolute and unchanging. • The job of a scientist is to find support for his or her hypothesis. • Scientists are completely objective in their evaluation of scientific ideas.

3. Some additional questions • Is the theory of evolution any different from intelligent design? • Are psychotropic therapies different from magnet therapy, reike, aromatherapy, or massage therapy?

4. Why is science different • Science isn’t just a collection of facts • Falsification • Determinism • Parsimony • Systematic observations/Empiricism • Asks answerable questions • Public knowledge • Tentative conclusions • Based on theories that can be refuted

5. Science is flawed: People are flawed • People are not objective; they are biased • Choice of study • How it is studied • Previous beliefs • Expectations • Information processing/How evidence is evaluated • Motivational • selective attention, selective recall, confirmation bias • Desire for social consensus • Illusory correlations and personal contact

6. Science is flawed: Research methods are flawed • There is no such thing as the perfect research study • Measurement • Observation • Hypotheses and predictions • Inferences drawn from observations • People do science • Still, what’s the alternative?!

7. Can we really know anything? • The relativistic view: • All views are equally valid, no standpoint is privileged over the other. • Fine if we are talking about human rights. Kinda fishy when applied to science.

8. Ways of knowing/Reasons for holding a viewpoint or position • Authority • Anecdote • Direct experience/ observation • Intuition • Faith, inspiration, emotions, gut feelings • Deduction • Logic, reason Systematic observation (empiricism) + Logic/Reason = Scientific Method Which method is the most valid? The most convincing?

9. Psychology & Soft vs. Hard Science • The science of behavior and mental processes • Contrast • Sociology, anthropology, economics, philosophy • Biology, chemistry, physics • Hard sciences are seen as more rigorous because of two beliefs 1) small things provide more truth about the world than bigger things, 2) observable things are easier to measure than non-observable things • People in psychology do it too—just talk to a neuroscientist! • Resist reduction!

10. Theories • What is a theory? • How does a theory differ from a hypothesis?

11. Theories • Testable framework for describing the behavior of a related set of social phenomena • Capable of predicting (and often explaining or describing) • And capable of being tested through experiment or otherwise falsified (disproved) through empirical methods. • Theories do not equal hypotheses or guesses!

12. Hypotheses • Specific prediction based on a theory • Alarge number of more specific hypotheses may be logically bound together by just one or two theories

13. Theory: Evolution Hypothesis (based on Natural selection): • Fishes with red tails are really healthy, therefore • Fishes with really red tails will get more sexual partners Natural Selection Heredity Variations

14. A little philosophy of science • Sir Karl Popper • Advances in knowledge can only come from falsification • We can improve our understanding via skepticism and by thinking of multiple explanations for stuff

15. Popper: Falsification • Theories and hypothesis cannot be proved • All swans are white • Evolution • Newton’s theory of relativity TheoryTheory Consistent result - Inconsistent result = ??= ??

16. Kuhn: Scientific Revolutions • Normal science vs extraordinary science • Good science/revolutionary science is all about paradigm shifts • Examples of paradigm shifts in psychology?

17. Theories • Good theories have some things in common: • Make unique predictions • Provide interesting/useful explanations • Overtime, converging evidence supports the theory • The theory has not been refuted

18. Basic vs. Applied Theories and Research • Basic • Tests theories • Strives to understand basic processes of thought, emotion, or behavior • Most often interested causes (experimental research designs) • Applied • Isn’t always theory driven • Interested in solving problems or issues • All sorts of research designs are used—whatever works

19. Statz in the spin cycle • Doing research with people • Individual differences = (Error) Variance !! • Dealing with error variance • Random sampling (sort of) • Random assignment • Measurement of potential extraneous variables • Control • Keep everything the same between conditions except the thing you are manipulating • Sufficient sample size

20. A mean without a standard deviation • Is like a day without sunshine • Means by themselves provide little information

21. Variance

22. Hypothetical Population

23. Sample from population • Normal distributions

24. Normal Curve: Means and SD’s • Sample scores from a population of scores usually form a normal curve (bell shaped) • M = Average = Sum of numbers/# of numbers • SD = everyone’s (standard) deviation from the mean • Variability • Spread • Measure of difference between each score and the mean

25. Subjective Well Being

26. Every inferential statistic Difference in Means (group B – group A) Variability (variability of scores in group B – variability of scores in group A) If the number is big then it’s probably not due to chance.

27. The P word • The statistic (t F r and other variations) are associated with p-values. • P-value = probability of null hypothesis given the finding Pr(ho/h1) • Probability that the effect (data supporting your hypothesis) is due to chance • Small p-value means your finding is probably not due to chance

28. The null • Why do we never “accept” the null or “prove” the null • P(ho) is more than a tasty soup

29. Effect Size Measure of the size of your effect (e.g., how big was your difference?) The ‘standard difference’ between means d = M1 - M2 / s Cohen Large effects = 0.8 Medium Effect = 0.5 Small Effect = 0.2

30. Write your answers to the following on a sheet of paper. True or False • Science is a collection of facts • Hard sciences are more rigorous and scientific than soft sciences. • Scientific ideas are absolute and unchanging. • The job of a scientist is to find support for his or her hypothesis. • Scientists are completely objective in their evaluation of scientific ideas.

31. Research Methods • Assessment