Class 5 and 6

Class 5 and 6 PowerPoint PPT Presentation

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The first team project (oral): Business idea proposal. 15 minute presentation5% of your total gradeIntroduce your team's business itemsThree criteriaInnovativenessDo-abilityExistence of market for the product/service. Agenda. Team introductionCorrelationTeam exerciseQuiz. Variables. An inte

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Class 5 and 6

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1. Class 5 and 6 Correlation Correlation & Causation Three scientific methods

2. The first team project (oral): Business idea proposal 15 minute presentation 5% of your total grade Introduce your teams business items Three criteria Innovativeness Do-ability Existence of market for the product/service

3. Agenda Team introduction Correlation Team exercise Quiz

4. Variables An intervening (mediating) variable Transmits the effects of a prior variable to a subsequent variable (A?B?C) Helps us understanding why an how A affects C A moderating (interaction) variable Governs or limits the relationship between two other constructs A causes B under some conditions

5. Diagram An intervening (mediating) variable

6. Graphical Depiction Click here for the excel File

7. Relationship btw two variables Covariance Association between two variables based on multiple cases Sensitive to units Correlation Linear association between two variables Correlation coefficient: r Unit free (-1 < r < 1)

8. Correlation Exercise In-Class activity Quiz

9. Quiz Question In one department of a design company, a manager named Sue observes that the level of absenteeism is pretty high. Sue knows that some people prefer to work at home; nevertheless, she is concerned that absenteeism from the office will hinder the performance of the designers. So, she decides to do a correlational study looking at absenteeism (the number of absences in one month) and performance (the number of designs accepted).

10. Quiz (2)

11. Quiz (3) Mean Variance Standard deviation Covariance Correlation

12. Quiz (4) Findings: Absenteeism and performance has negative association Conclusion (causal relationship) Does absenteeism lead to low performance? Does low performance lead to absenteeism? Is there another possible explanation?

13. Quiz (5)

14. Quiz (6)

15. Correlational Study Correlation coefficient measures only the strength of association between two variables It does not tell us about causality The length of a womens skirts and stock market price Cannot rule out other possible explanation High association between polio and Coke

16. Correlational Study (Cont.)

17. Correlational Study (Cont.)

18. Correlational Study (Cont.) No controlled manipulation Manipulating independent variable at our discretion, holding other possible causes of dependent variable constant Time Longitudinal study Observation of changes in X in time 1 correlates changes in time 2

19. Correlational Study (Cont.)

20. Correlational Study (Cont.)

21. Scientific vs. Non-scientific

22. Scientific Methods The objective Accurate depiction of (causal) relationship Causal relationship requires: Correlation Time sequence Eliminate other possible causes

23. Scientific Methods (Cont.) Types Naturalistic observation Field survey research Cross-sectional, correlational Longitudinal Experiments Field Laboratory

24. Naturalistic Observation

25. Field Survey Research

26. Why (Field or Lab) Experiment? Why experiment? To determine what causes what How do we see the causal relationship? Observing whether changing X will produce a change in Y How do we know that changes occurred? By comparing two different groups

27. Debriefing In Class Experiment What are we interested in? The effects of leader presence in a group activity in individual learning Specific hypothesis in the next slide What causes the variation of the amount? Groups with leaders and without leaders Causal relationship The presence or absence of leader in the group during the correlation exercise will cause the difference in individual learning of the concept of correlation

28. Research Hypotheses Hypothesis H1: Leader present group will perform better than leader absent group H2: Prior statistical knowledge will lead to better performance H3: The influence of prior statistical knowledge on performance will be stronger for leader present group than for leader absent group

29. Three Major Criteria for Good Experiments Random assignment Manipulation Control

30. Random Assignment What is it? To assign participants into two different conditions Without it one really does not have an experiment (Campbell & Stanley, 1963) Does RA guarantee that the two groups are alike before manipulation No Then why? Any differences due to the two groups will be due to the random process, which is unrelated with exp

31. Manipulation Manipulating independent variable Presence of leader Two groups Experimental group (Manipulation) Control group (No Manipulation) How are we sure that there was manipulation? Manipulation check

32. Control Holding an extraneous variable An extraneous variable A variable other than an independent variable that may influence the results of an experiment What can be the example of extraneous variables in our experiment?

33. Pretest-posttest Control Group Design

34. Posttest-only Control Group Design

35. Experiment Result All the hypotheses were not supported However......

36. Statistical Significance (old data)

37. In Class Exercise As a group, discuss the following: What can you improve our class experiment given the three criteria of good experiment? In your opinion, what kind of biases existed from your side or my side (experimenter) during the experiment?

38. Reliability and Validity Reliability Consistency of measurement Example: Test-retest reliability Split-half reliability Coefficient alpha Validity The degree to which a research study is actually measuring what it claims to be measuring Generalizability The degree to which a research findings can apply to a different people, time, and settings

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