1. Introduction to Statistics for the Social Sciences SBS200 - Lecture Section 001, Spring 2018 Room 150 Harvill Building 9:00 - 9:50 Mondays, Wednesdays & Fridays.
Welcome
4/2/18

2. Lecturer’s desk Projection Booth Screen Screen Harvill 150 renumbered
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Harvill 150
renumbered
table 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Projection Booth
Left handed desk

4. Before next exam (April 6th)
Schedule of readings
Before next exam (April 6th)
Please read chapters in OpenStax textbook
Please read Chapters 2, 3, and 4 in Plous
Chapter 2: Cognitive Dissonance
Chapter 3: Memory and Hindsight Bias
Chapter 4: Context Dependence
Study guide now online

5. Lab sessions
Project 3
Due this week
at beginning of lab

6. Homework #23
Postponed until
Wednesday

7. Let’s do another one
Test to see whether there is a difference in the number of units taken
by 5 different majors: Geography, Sociology, Nutrition, Communication and Criminal Justice. We measured 60 students (12 students per major)

8. Writing Assignment – ANOVA – Part Three
1. Complete this ANOVA table
2. Find the critical F value from the table
3. Is there a main effect of major on number of units taken?
4. Is “p< 0.05”? SS df
= MS
ANOVA table
Source SS df MS F
5. Write a summary statement
of findings (all three parts)
Between
218.23 ? ? ?
Within
759.42 ? ?
Total
977.65 ?

9. Degrees of Freedom Between
Degrees of Freedom Within
(always “round down”)

10. Writing Assignment – ANOVA – Another Example
1. Complete this ANOVA table
2. Find the critical F value from the table
3. Is there a main effect of major on number of units taken?
4. Is “p< 0.05”? SS df
= MS
ANOVA table
Source SS df MS F
5. Write a summary statement
of findings (all three parts)
Between
218.23 4
54.56
3.95
Within
759.42 55
13.81
Total
977.65 59

11. Make decision whether or not to reject null hypothesis
Observed F(4,55) = 3.95
Critical F(4,55) = 2.56
3.9 is larger than our critical of 2.56
so, we do reject the null hypothesis
Observed F(4,55) = 3.95
Conclusion: There appears to be a main effect of type of
major on number of units taken in school
The average number of units taken by Geography, Sociology,
Nutrition, Communication and Criminal Justice majors are 11.92,
12.50, 8.08, and 8.58 respectively. An ANOVA was conducted
and there appears to be a main effect of the number of units taken
as a result of the different majors. F(4,55) = 3.95; p < 0.05

12. Let’s do similar problem Using MS Excel
Test to see whether there is a difference in the number of units taken
by 5 different majors: Geography, Sociology, Nutrition, Communication and Criminal Justice. We measured 60 students (12 students per major)

13. Let’s do similar problem Using MS Excel
Test to see whether there is a difference in the number of units taken
by 5 different majors: Geography, Sociology, Nutrition, Communication and Criminal Justice. We measured 60 students (12 students per major)

14. Let’s do similar problem Using MS Excel
Test to see whether there is a difference in the number of units taken
by 5 different majors: Geography, Sociology, Nutrition, Communication and Criminal Justice. We measured 60 students (12 students per major)

15. Let’s do similar problem Using MS Excel
Test to see whether there is a difference in the number of units taken
by 5 different majors: Geography, Sociology, Nutrition, Communication and Criminal Justice. We measured 60 students (12 students per major)
SSbetween
dfbetween
218 4
=55
MSbetween
MSwithin
“Sum of Squares”
# groups - 1 55
13.8
=3.95
5-1=4
# scores - # of groups
759 55
=13.8
SSwithin
dfwithin
60 – 5 = 55
# scores - 1
60-1=59

16. The average number of units taken by Geography, Sociology,
Nutrition, Communication and Criminal Justice majors are 11.92,
12.50, 8.08, and 8.58 respectively. An ANOVA was conducted
and there appears to be a main effect of the number of units taken
as a result of the different majors. F(4,55) = 3.95; p < 0.05

17. Hand in your writing assignment

18. In a one-way ANOVA we have three types of variability.
Let’s try one
In a one-way ANOVA we have three types of variability.
Which picture best depicts the random error variability (also known as the within variability)?
a. Figure 1
b. Figure 2
c. Figure 3
d. All of the above 1.
correct 2. 3.

19. In a one-way ANOVA we have three types of variability.
Let’s try one
In a one-way ANOVA we have three types of variability.
Which picture best depicts the between group variability?
a. Figure 1
b. Figure 2
c. Figure 3
d. All of the above
correct 1. 2. 3.

20. Which figure would depict the largest F ratio a. Figure 1 b. Figure 2
Variability between groups
F =
Let’s try one
Variability within groups
“F ratio” is referring
to "observed F”
Which figure would depict the largest F ratio
a. Figure 1
b. Figure 2
c. Figure 3
d. All of the above
correct 1. 2. 3.

21. Winnie found an observed F ratio of .9, what should she conclude?
Let’s try one
Winnie found an observed F ratio of .9, what should she conclude?
a. Reject the null hypothesis
b. Do not reject the null hypothesis
c. Not enough info is given
correct 1. 2. 3.

22. Winnie found an observed z of .74, what should she conclude?
If your observed z is within
one standard deviation of the mean,
you will never reject the null
Let’s try one
Winnie found an observed z of .74, what should she conclude?
(Hint: notice that .74 is less than 1)
a. Reject the null hypothesis
b. Do not reject the null hypothesis
c. Not enough info is given
correct x x
small observed z score
small observed z score

23. Winnie found an observed t of .04, what should she conclude?
Let’s try one
Winnie found an observed t of .04, what should she conclude?
(Hint: notice that .04 is less than 1)
a. Reject the null hypothesis
b. Do not reject the null hypothesis
c. Not enough info is given
correct x
small observed t score

24. F(4, 25) = 3.12; p < 0.05 Let’s try one
How many
observations within
each group?
Let’s try one
An ANOVA was conducted comparing different types of solar cells and there appears to be a significant difference in output of each (watts) F(4, 25) = 3.12; p < In this study there were __ types of solar cells and __ total observations in the whole study?
a. 4; 25
b. 5; 30
c. 4; 30
d. 5; 25
F(4, 25) = 3.12; p < 0.05
correct
# groups - 1
# scores - # of groups
# scores - 1

25. F(4, 25) = 3.12; p < 0.05 Let’s try one
An ANOVA was conducted comparing different types of solar cells and there appears to be significant difference in output of each (watts) F(4, 25) = 3.12; p < In this study ___
a. we rejected the null hypothesis
b. we did not reject the null hypothesis
correct
F(4, 25) = 3.12; p < 0.05
Observed F
bigger than
Critical F
p < .05

26. F(4, 25) = 3.12; p < 0.05 Let’s try one
An ANOVA was conducted comparing different types of solar cells. The analysis was completed using an alpha of But Julia now wants to know if she can reject the null with an alpha of at In this study ___
a. we rejected the null hypothesis
b. we did not reject the null hypothesis
correct
F(4, 25) = 3.12; p < 0.05
Comparison of the Observed F and Critical F
Is no longer are helpful because
the critical F is no longer correct.
We must use the p value
p < .05
p > .01

27. Let’s try one
An ANOVA was conducted comparing home prices in four neighborhoods (Southpark, Northpark, Westpark, Eastpark) .
For each neighborhood we measured the price of four homes. Please complete this ANOVA table. Degrees of freedom between is _____; degrees of freedom within is ____
a. 16; 4
b. 4; 16
c. 12; 3
d. 3; 12
correct .

28. Let’s try one
An ANOVA was conducted comparing home prices in four neighborhoods (Southpark, Northpark, Westpark, Eastpark) .
For each neighborhood we measured the price of four homes. Please complete this ANOVA table. Mean Square between is _____; Mean Square within is ____
a. 300, 300
b. 100, 100
c. 100, 25
d. 25, 100
correct .

29. Let’s try one
An ANOVA was conducted comparing home prices in four neighborhoods (Southpark, Northpark, Westpark, Eastpark) .
For each neighborhood we measured the price of four homes. Please complete this ANOVA table. The F ratio is:
a. .25
b. 1
c. 4
d. 25
correct .

30. a. reject the null hypothesis b. not reject the null hypothesis
Let’s try one
An ANOVA was conducted comparing home prices in four neighborhoods (Southpark, Northpark, Westpark, Eastpark) .
For each neighborhood we measured the price of four homes. Please complete this ANOVA table, alpha = We should:
a. reject the null hypothesis
b. not reject the null hypothesis
correct
Observed F
bigger than
Critical F
p < .05

31. Thank you!
See you next time!!