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
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 team’s business items
Existence of market for the product/service
3. Agenda Team introduction
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
Linear association between two variables
Correlation coefficient: r
Unit free (-1 < r < 1)
8. Correlation Exercise In-Class activity
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
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 women’s 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
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:
Eliminate other possible causes
23. Scientific Methods (Cont.) Types
Field survey research
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
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
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
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
Experimental group (Manipulation)
Control group (No Manipulation)
How are we sure that there was manipulation?
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
The degree to which a research study is actually measuring what it claims to be measuring
The degree to which a research findings can apply to a different people, time, and settings