1. Introduction to Statistics for the Social Sciences SBS200 - Lecture Section 001, Fall 2017 Room 150 Harvill Building 10: :50 Mondays, Wednesdays & Fridays.
Welcome

2. Lecturer’s desk Projection Booth Screen Screen Harvill 150 renumbered
Row A 15 14
Row A 13 3 2 1
Row A
Row B 23 20
Row B 19 5 4
3 2 1
Row B
Row C 25 21
Row C 20 6 5 1
Row C
Row D 29 23
Row D 22 8 7 1
Row D
Row E 31 23
Row E 23 9 8 1
Row E
Row F 35 26
Row F 25 11 10 1
Row F
Row G 35 26
Row G 25 11 10 1
Row G
Row H 37 28 27 13
Row H 12 1
Row H 41 29 28 14
Row J 13 1
Row J 41 29
Row K 28 14 13 1
Row K
Row L 33 25
Row L 24 10 9 1
Row L
Row M 21 20 19
Row M 18 4 3 2 1
Row M
Row N 15 1
Row P 15 1
Harvill 150
renumbered
table 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Projection Booth
Left handed desk

3. Schedule of readings Before next exam (September 22nd)
Please read chapters in OpenStax textbook
Please read Appendix D online On syllabus this is referred to as online readings 1
Please read Chapters 1, 5, 6 and 13 in Plous
Chapter 1: Selective Perception
Chapter 5: Plasticity
Chapter 6: Effects of Question Wording and Framing
Chapter 13: Anchoring and Adjustment

4. writing assignment forms notebook and clickers to each lecture
Remember bring your
writing assignment forms
notebook and clickers to each lecture

5. Even if you have not yet registered your clicker you can still participate

7. Labs continue next week
Lab sessions
Everyone will want to be enrolled
in one of the lab sessions
Labs continue next week
Exam 1 Review

8. Overview Frequency distributions
The normal curve
Mean, Median,
Mode, Trimmed Mean
Standard deviation,
Variance, Range
Mean Absolute Deviation
Skewed right, skewed left
unimodal, bimodal, symmetric

9. Based on difference from the mean
Deviation scores: The amount by which each
observation deviates from the mean (above or below)
Deviation scores
Diallo is 0”
(x - µ)
Preston is 2”
Mike is -4”
Hunter is -2
Standard deviation: The average amount by which observations deviate on either side of their mean
Shea is 4
David is 0”
Remember
It’s relative
to the mean
5’8” 5’10” 6’0” 6’2” 6’4”
Based on difference from the mean

10. How far away is each score from the mean?
Standard deviation: The average amount by which
observations deviate on either side of their mean
Deviation scores
(x - µ)
Diallo is 0”
Preston is 2”
How far away is each score from the mean?
Mike is -4”
Hunter is -2
Shea is 4
Mean
Step 1
Find the mean
David is 0”
Diallo
Step 2
Find each deviation score
Preston
Σ (x - µ) = ?
Shea
Mike
5’8” ’0” = - 4”
5’9” ’0” = - 3”
5’10’ - 6’0” = - 2”
5’11” - 6’0” = - 1”
6’0” ’0 = 0
6’1” ’0” = + 1”
6’2” ’0” = + 2”
6’3” ’0” = + 3”
6’4” ’0” = + 4”
Step 3
Square each deviation score
And add them up
Step 4
Divide by n and take square root
Σ(x - x) 2 2
Σ(x - x) = 0
Σ(x - µ) N
Σ(x - µ) 2
Σ(x - µ) = 0

11. These would be helpful to know by heart – please memorize
Standard deviation: The average amount by which
observations deviate on either side of their mean
These would be helpful to know by heart – please memorize
these formula

12. What do these two formula have in common?
Standard deviation: The average amount by which observations
deviate on either side of their mean
What do these two formula have in common?

13. What do these two formula have in common?
Standard deviation: The average amount by which observations
deviate on either side of their mean
What do these two formula have in common?

14. How do these formula differ?
Standard deviation: The average amount by which observations
deviate on either side of their mean
“n-1” is
Degrees of Freedom”
How do these formula differ?

15. “Sum of Squares” “Sum of Squares” “Sum of Squares” “Sum of Squares”
Standard deviation: The average amount by
which observations deviate on either side of their mean
“Sum of Squares”
“Sum of Squares”
“Sum of Squares”
“Sum of Squares”
Diallo is 0”
Mike is -4”
Hunter is -2
Shea is 4
David 0”
Preston is 2”
Deviation scores
Remember, it’s relative to the mean
“n-1” is
“Degrees of Freedom”
“n-1” is
“Degrees of Freedom”
Generally, (on average) how far away is each score from the mean?
Based on difference from the mean
Mean
Remember, We are thinking in terms of “deviations”
Diallo
Please memorize these
Preston
Shea
Mike

16. Raw scores, z scores & probabilities
Please note spatially where 1 standard deviation falls on the curve

17. Raw scores, z scores & probabilities
Please note spatially where 1 standard deviation falls on the curve
68%
95%
99.7%

18. These would be helpful to know by heart – please memorize areas
1 sd above and below mean
68%
2 sd above and below mean
95%
3 sd above and below mean
99.7%
These would be helpful to know by heart – please memorize areas

19. Summary of 7 facts to memorize

20. We estimated and calculated the standard deviation
Now let’s use it as a
measure of counting

21. Raw scores, z scores & probabilities
1 sd above and below mean
68%
z = +1
z = -1
Mean = 50
σ = 10
If we go up one standard deviation
z score = +1.0 and raw score = 60
If we go down one standard deviation
z score = -1.0 and raw score = 40

22. Raw scores, z scores & probabilities
2 sd above and below mean
95%
z = -2
z = +2
Mean = 50
σ = 10
If we go up two standard deviations
z score = +2.0 and raw score = 70
If we go down two standard deviations
z score = -2.0 and raw score = 30

23. Raw scores, z scores & probabilities
3 sd above and below mean
99.7%
z = +3
z = -3
Mean = 50
σ = 10
If we go up three standard deviations
z score = +3.0 and raw score = 80
If we go down three standard deviations
z score = -3.0 and raw score = 20

24. z score = raw score - mean standard deviation
If we go up one standard deviation
z score = +1.0 and raw score = 105
z = -1
z = +1
68%
If we go down one standard deviation
z score = -1.0 and raw score = 95
If we go up two standard deviations
z score = +2.0 and raw score = 110
z = -2
95%
z = +2
If we go down two standard deviations
z score = -2.0 and raw score = 90
If we go up three standard deviations
z score = +3.0 and raw score = 115
99.7%
z = -3
z = +3
If we go down three standard deviations
z score = -3.0 and raw score = 85
z score: A score that indicates how many standard deviations
an observation is above or below the mean of the distribution
z score = raw score - mean
standard deviation

26. Writing Assignment
– Pop Quiz

27. Writing Assignment
– Pop Quiz

28. Writing Assignment – Pop Quiz Distance from the mean X Taller 2 inches
Preston is 2” taller than the mean (taller than most)
Taller
2 inches
Shorter X
Mike is 4” shorter than the mean (shorter than most)
Shorter
4 inches
Taller X
Equal to mean
Diallo is exactly same height as mean (half taller half shorter)
0 inches
Half are Shorter

29. Writing Assignment – Pop Quiz Sigma – standard deviation - population
Parameter
mu – a mean – an average - population
Parameter
x-bar – a mean – an average - sample
statistic
s – standard deviation - sample
statistic
The number of “standard deviations” the score is from the mean
population
Sigma squared and s squared - variance
Sigma is parameter (population) s is statistic (sample)
Deviation scores
(x-µ) for population (parameter) (x-x) is statistic (sample)
Sum of squares
On left is statistic on right is parameter
Standard deviation
s is statistic sigma is parameter
Degrees of freedom
sample

30. If it is complete and correct, hand it in now

31. z score = raw score - mean standard deviation
If we go up one standard deviation
z score = +1.0 and raw score = 105
z = -1
z = +1
68%
If we go down one standard deviation
z score = -1.0 and raw score = 95
If we go up two standard deviations
z score = +2.0 and raw score = 110
z = -2
95%
z = +2
If we go down two standard deviations
z score = -2.0 and raw score = 90
If we go up three standard deviations
z score = +3.0 and raw score = 115
99.7%
z = -3
z = +3
If we go down three standard deviations
z score = -3.0 and raw score = 85
z score: A score that indicates how many standard deviations
an observation is above or below the mean of the distribution
z score = raw score - mean
standard deviation

32. Thank you!
See you next time!!