Introductory lectures 2: The Role and Structure of Science

1. Introductory lectures 2: The Role and Structure of Science • What does science do? • The core features of a research study. • Overall Research approaches. Revised 2/7/14 Right click for “full Screen” or “end show”. Left click to proceed,

2. Introductory lectures 2: The Role and Structure of Science • What does science do? • The core features of a research study. • Overall Research approaches.

3. What does science do? What does Science do? Describe the world Made predictions(hypotheses) Develop & test theories Apply findings or theories Section Overview

4. 1. Describing the world Science: Description Prediction Theory Application • 1. Qualitative Description • Simple observation: Describe what goes on “in the wild”. • Record patterns of behavior in specific groups or places. • Valuable for formulating hypotheses.

5. 1. Describing the world Science: Description Prediction Theory Application • 2. Quantitative description • Tracking patterns of behavior using numbers • Surveys, polls… • Archival data. • Useful for both developing and testing hypotheses.

6. Examples of Descriptive Research Science: Description Prediction Theory Application • Categories of mental illnesses. • Epidemiology; Behavior in different groups • Where is AIDS most common in the U.S.? • Uniform crime rates. • Taxonomies: Behavioral categories • Personality "types”.

7. Descriptive research Paleontology attempts to accurately describe the predecessors of humans to understand evolution • Carefully describing specimens and the conditions where they are found can: • Produce insights into environmental change and evolution • Allow us to test hypotheses & develop theory. E X A M P L E

8. 2. Science and Predictions Science: Description Prediction Theory Application  What test score best predicts college success?  Can I predict which employees will steal? • These applications (should) stem from a theory. • Verbal & quantitative aptitude  academic success • A specific personality constellation  criminality… • That is (or should be…) supported by empirical evidence. Practical applications:

9. 2. Science and Predictions Science: Description Prediction Theory Application • Testing hypotheses: • An hypothesis is a prediction • Correlational research; • I predict that people scoring low on a measure of science education will be prone to irrational beliefs. • Experimental research; • I predict that providing science education will decrease people’s irrational beliefs. Practical applications:

10. Predictions and theory development Correlating certain anatomical features of “proto-humans” with physical environments can test or develop theories about natural selection pressures. Scientists can then predict (test hypotheses about) the types of fossils that should appear in different places. E X A M P L E

11. 3. Developing & Testing Theory Science: Description Prediction Theory Application Theory is the ‘bottom line’ of science • Identify basic (Ψ, physical…) processes… • that are systematically related… • that show how or why something works. i.e., what “causes” a phenomenon in the natural world.

12. Predictions and theory development New data have led us to rethink the basic process of human evolution (i.e., change our theories) • from a simple progression • to a widening “bush” of parallel species. E X A M P L E

13. Predictions and theory development The effectspaleontologists see in their data lead them to rethink the shape of the evolutionary tree that must cause them. This leads to a reconsideration of basic processes – e.g., selection pressures - that shape human evolution. E X A M P L E

14. 3. Testing theory: Mediating effects Science: Description Prediction Theory Application What might lead to irrational beliefs? A. We describe a simple empirical effect (correlation): Social & economic uncertainty Irrational beliefs (Social uncertainty predicts more widespread irrational beliefs)

15. 3. Testing theory: Mediating effects Science: Description Prediction Theory Application What might lead to irrational beliefs? B. How does this work? What Theory may explain this? Uncertainty Need to feel control Irrational beliefs (Superstition may help people feel in control of their world under times of uncertainty.)

16. 3. Testing theory: Mediating effects Science: Description Prediction Theory Application What might lead to irrational beliefs? B. How does this work? What Theory may explain this? Uncertainty Need to feel control Irrational beliefs Critical thinking (…particularly among people with lower critical thinking skills.)

17. Theory and processes Uncertainty Need to feel control Irrational beliefs Critical thinking • Our theory helps identify basic economic or psychological processes; • specifies how they may be related; • and where / how we may change the outcome

18. Theory and processes Uncertainty Need to feel control Irrational beliefs • Why hypotheses does this theory contain? • How might you test them? • How else might you think of this theory? • What other variables may be important? • How might you change some of the arrows? Critical thinking

19. 4. Applications of theory Science: Description Prediction Theory Application I use theory (and evidence) about learning to design this course… We using practices derived from basic learning theory to “teach” people to no longer have phobias. • …or we can use an intervention study to actually test a theory Behavioral or biomedical interventions often compare treatments based on differing theories. We use theory to design interventions

20. Theories and interventions One theory of smoking involves social networks: people are influenced by their friends’ smoking E X A M P L E An intervention study of smokingcessation showed that having people quit with their friends may be more effective that quitting by themselves.

21. Theories and interventions The theory was that social networks influence smoking. The hypothesis was that a network-based cessation program would work better E X A M P L E than an individual program. Testing the hypothesis both: • Pointed to a practical intervention approach; • Supported the theory that social networks are important to smoking and quitting.

22. The values of science & empiricism • Empirical description • Can take multiple forms; qualitative, quantitative… • Important for its own sake, and for developing hypotheses • Predictions • Core feature of a hypothesis; • A priori predictions force us to clearly test our ideas • Developing and testing theory • Central role of science; explaining how or why a natural process works. • Applications of theories • Expand and elaborate a theory through applying it • Important for advances in, e.g., technology, behavioral science SUMMARY

23. Elements of science, review 1 • Epidemiology is… • A way of classifying people or behaviors • The study of how frequent a behavior or “condition” is across a population. • The identification of basic psychological principles that underlie important behaviors • A core feature of a hypothesis.

24. Elements of science, review 2 • A Theory is… • A way of classifying people or behaviors • The study of how frequent a behavior or “condition” is across a population. • The identification of basic psychological principles that underlie important behaviors • A core feature of a hypothesis.

25. Elements of science, review 3 • A Prediction is… • A way of classifying people or behaviors • The study of how frequent a behavior or “condition” is across a population. • The identification of basic psychological principles that underlie important behaviors • A core feature of a hypothesis.

26. Elements of science, review 4 • A Taxonomy is… • A way of classifying people or behaviors • The study of how frequent a behavior or “condition” is across a population. • The identification of basic psychological principles that underlie important behaviors • A core feature of a hypothesis.

27. Introduction to science, 5 • What does science do? • Core features of a research study. • Overall Research approaches. 

28. The overall “flow” of research Phenomenon - Larger question the research addresses Theory - Explanatory processes & how they are related • Hypothesis • Concrete variables • Specific prediction Section Overview • Methods / Data • Operational definitions • Study procedures Results - Hypothesis-wise analysis of outcomes • Discussion & Conclusion • Relate results back to theory • Study limitations & Future studies

29. Research Flow Phenomenon - Larger question the research addresses What needs explaining? Why is it important? Theory - Explanatory processes & how they are related How / why do I think it works? • Hypothesis • Concrete variables • Specific prediction What is my specific prediction? • Methods / Data • Operational definitions • Study procedures What concrete evidence or data will I collect? Results - Hypothesis-wise analysis of outcomes What was the outcome? Hypothesis supported? What do the results mean for the theory? What is unanswered? • Discussion & Conclusion • Relate results back to theory • Study limitations & Future studies

30. Research Flow Phenomenon - Larger question the research addresses The research flow begins with broad, abstract questions Theory - Explanatory processes & how they are related • Hypothesis • Concrete variables • Specific prediction Gets more specific & concrete • Methods / Data • Operational definitions • Study procedures Results - Hypothesis-wise analysis of outcomes Then back to a more general discussion. • Discussion & Conclusion • Relate results back to theory • Study limitations & Future studies

31. Core features of research: Theory. Phenomenon - Larger question the research addresses Theory - Explanatory processes & how they are related • Hypothesis • Concrete variables • Specific prediction Theory: • Methods / Data • Operational definitions • Study procedures • Abstract statement of how basic processes relate to each other… • Answers howor whythe phenomenon “works.” Results - Hypothesis-wise analysis of outcomes • Discussion & Conclusion • Relate results back to theory • Study limitations & Future studies

32. Theory These are basic physical or behavioral processes. They are the building blocks of theories. • Economic uncertainty • Cognitive style • Stress • Gravity • Learning…

33. Theory • They are abstract: • We cannot actually “see” gravity. • We just see what it does (stuff falls). • Economic uncertainty • Cognitive style • Stress • Gravity • Learning…

34. Theory • Gravity is a Hypothetical Construct: • Central to our understanding of nature • We measure and understand it by observing its effects on the world. • Economic uncertainty • Cognitive style • Stress • Gravity • Learning…

35. Theory • A theory is a statement about how these hypothetical constructs are related • to each other • to some concrete event

36. How do we use theory in research? • Test a theory: Do women who feel strong stereotype threat about math actually do worse? • Compare theories: Which best explains women’s statistics performance: stereotype threat or social role learning? • Extend an established theory: Can stereotype threat help us explain athletic as well as academic performance? • Apply a theory: Can I create instructions that relieve stereotype threat for women during statistics?

37. Core features of research: Hypotheses. Phenomenon - Larger question the research addresses Theory - Basic Ψprocesses we think explain the phenomenon • Hypothesis • Concrete variables that express the Ψ processes • Specific prediction Hypothesis: • Methods / Data • Operational definitions • Study procedures • A prediction • That is potentially falsifiable. Results - Hypothesis-wise statistical analysis of study outcomes • Discussion & Conclusion • Relate results back to theory • Study limitations & Future studies

38. Hypothesis • An hypothesis is a Prediction • It links variables derived from the theory. • It implicitly specifies your idea of cause and effect. • …that is potentially falsifiable(see text for discussion) • Can be conceivably / logically shown to be untrue • Specific enough to be tested

39. Hypothesis • So hypotheses are expressed in control terms: • IFI make people relaxed thentheir fear and loathing of statistics will decrease. • Measurement studiesdo not manipulate anything. • Hypotheses are expressed as a relation. • People who are (already) relaxed will tend to fear statistics less. Measurement v. Experimental studies: • In experiments we manipulate the Independent Variable.

40. Core features of research: Methods. Methods: Phenomenon - Larger question the research addresses Theory - Basic Ψprocesses we think explain the phenomenon • Measurement or experimental procedures • Rely on Operational Definitions • Hypothesis • Concrete variables that express the Ψ processes • Specific prediction • Methods / Data • Operational definitions • Study procedures Results - Hypothesis-wise statistical analysis of study outcomes • Discussion & Conclusion • Relate results back to theory • Study limitations & Future studies

41. Methods • Turn our hypotheses into concrete variables • That we examine via specific procedures • Core element of scientific approach • Objective; designed to separate data from person • Public: multiple people participate in, challenge, or use scientific findings • Replicable: others can repeat or expand the study

42. Methods What is “depression”? What operations could assess it? Verbal behavior “vegetative”; sleep, eating Depression Appearance Suicide, drug use, work… Survey / questionnaire answers… We turn our hypotheses into variables via an operation definition.

43. Methods • What is “economic uncertainty”? • The unemployment rate? • Subjective attitude ratings? • What is “Stress”? • Heart rate & cortisol levels? • Speech patterns? OurOperation definitiondetermines what a variable “means” in our study.

44. Methods In Experiments we specify a manipulationthat defines the variable In Observational or descriptive research we define our variables by their measurement. • These reflect two main branches of research: MeasurementversusExperimental. We have two forms of operational definitions:

45. Methods • This is the independent variable • To test the hypothesis that stress impairs memory I may createstress in the lab via… • Shock. • Requiring a difficult performance in front of others. Are • shock (a physical threat) • and • performance (a social threat) • Equivalent ‘Stressors”?

46. Methods • I may measure stress levels in this class via: • A questionnaire scale • Heart rate • Anxious behavior, sleep loss, appetite change… Are • Equivalent measures of Stress? • Heart rate • and • sleep loss

47. Operationalizing “Stress” Does stress lead to illness? Measure the dependent variable • Infection post-exposure • Observed respiratory infections Manipulate the independent variable • Threatening information. • Shock. • Require difficult public performance. E X A M P L E Measure the predictor • Questionnaire scale on life events • Assess cardio-vascular reactivity Measure the outcome variable • Self-reported respiratory infections • Morbidity & mortality

48. Operationalizing “Stress” Does stereotype threat lower academic performance? Measure the dependent variable • Performance under highlighted & public vs. control conditions Manipulate the independent variable • Highlight group difficulties • Make the performance public E X A M P L E Measure the outcome variable • Performance over a course Measure the predictor • Questionnaire scale: • Anticipated group performance • Self-consciousness

49. Methods: Why use Operational Definitions? • What does “stress” mean? • Long v. short term? • Subjective v. life events? • How will you measure it? • Overt behavior? • Physical symptoms? • Subjective state? • What does “health” mean? • Long v. short term? • Positive v. symptoms? • How will you measure it? • Overt behavior? • Physical? • Psychological? • Any theory must be operationalized to be heuristically useful • Operational definitions orient us toward real world rather than vague abstractions I think stress makes people less healthy

50. Methods: Why use Operational Definitions? • What does “stress” mean? • How will you measure it? • What does “health” mean? • How will you measure it? • For any study we need to think critically about what each term means, and how it is measured. • Any theory must be operationalized to be heuristically useful • Operational definitions orient us toward real world rather than vague abstractions I think stress makes people less healthy