1. Introduction to Statistics for the Social Sciences SBS200 - Lecture Section 001, Fall 2016 Room 150 Harvill Building 10: :50 Mondays, Wednesdays & Fridays.
Welcome

2. By the end of lecture today 9/12/16
Use this as your
study guide
By the end of lecture today 9/12/16
Characteristics of a distribution
Central Tendency
Dispersion
Introduction to Excel for Project 1

3. Homework Assignment 6 Please complete the homework modules on the D2L website
HW6 – Part 1 - Measures of Central Tendency
HW6 - Part 2 - Descriptive Statistics Deviation Scores
Due: Wednesday, September 14th

4. Schedule of readings Before next exam (September 23rd)
Please read chapters in OpenStax textbook
Please read Appendix D, E & F online On syllabus this is referred to as online readings 1, 2 & 3
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

5. Labs continue this week
Lab sessions
Everyone will want to be enrolled
in one of the lab sessions
Labs continue this week

6. Project 1 - Likert Scale - Correlations - Comparing two means (bar graph)
PowerPoint

15. Notice Gillian asked 1300 people
.10 x 1,000,000 = 100,000
130/1300 = .10
.10 10
100,000
.08 8
80,000
.10x100=10
.25 25
250,000
.35 35
350,000
.22 22
220,000
=1300

16. Review of Homework Worksheet
.10 10
100,000
.08 8
80,000
.25 25
250,000
.35 35
350,000
.22 22
220,000

18. Review of Homework Worksheet
Strong
Negative
Review of Homework Worksheet
Down
-.9 9 8 7 6
Dollars Spent 5 4 3 2 1 10 20 30 40 50
Age

19. Review of Homework Worksheet
Strong
Negative
Review of Homework Worksheet
Down
=correl(A2:A11,B2:B11) =

20. Review of Homework Worksheet
Strong
Negative
Review of Homework Worksheet
Down
This shows a strong negative relationship (r = ) between the amount spent on snacks and the age of the moviegoer
Description includes:
Both variables
Strength (weak,moderate,strong)
Direction (positive, negative)
Correlation r (actual number)
=correl(A2:A11,B2:B11) =

21. Review of Homework Worksheet
Do not hand it in unless it:
Has 3 graphs printed correctly
Is correct, complete and stapled
If it is not complete and correct, consider this an “extension” and hand it in next time
Strong
Negative
Review of Homework Worksheet
Down
If it is complete and
correct, hand it
in now

22. Overview Frequency distributions
The normal curve
Challenge yourself as we work through characteristics of distributions to try to categorize each concept as a measure of
1) central tendency
2) dispersion or 3) shape
Mean, Median,
Mode, Trimmed Mean
Standard deviation,
Variance, Range
Mean Absolute Deviation
Skewed right, skewed left
unimodal, bimodal, symmetric
Review

23. Another example: How many kids in your family?
Number of kids in family
1 4
3 2
1 8
4 2
2 14 14 4 2 1 4 2 2 3 1 8

24. Mean: The balance point of a distribution. Found
Measures of Central Tendency (Measures of location) The mean, median and mode
Mean: The balance point of a distribution. Found
by adding up all observations and then dividing
by the number of observations
Mean for a sample:
Σx / n = mean = x
Mean for a population:
ΣX / N = mean = µ (mu)
Measures of “location”
Where on the number line the scores tend to cluster
Note: Σ = add up
x or X = scores
n or N = number of scores

25. Number of kids in family
Measures of Central Tendency (Measures of location) The mean, median and mode
Mean: The balance point of a distribution. Found
by adding up all observations and then dividing
by the number of observations
Mean for a sample:
Σx / n = mean = x
41/ 10 = mean = 4.1
Number of kids in family
1 4
3 2
1 8
4 2
2 14
Note: Σ = add up
x or X = scores
n or N = number of scores

26. How many kids are in your family? What is the most common family size?
Number of kids in family
1 3
1 4
2 4
2 8
2 14
How many kids are in your family?
What is the most common family size?
Median: The middle value when observations are
ordered from least to most (or most to least)

27. Number of kids in family
1 4
3 2
1 8
4 2
2 14
How many kids are in your family?
What is the most common family size?
Median: The middle value when observations are
ordered from least to most (or most to least)
1, 3, 1, 4, 2, 4, 2, 8, 2, 14 1, 1, 2, 2, 2, 3, 4, 4, 8, 14

28. Number of kids in family
1 3
1 4
2 4
2 8
2 14
Number of kids in family
1 4
3 2
1 8
4 2
2 14
How many kids are in your family?
What is the most common family size?
Median: The middle value when observations are
ordered from least to most (or most to least)
1, 3, 1, 4, 2, 4, 2, 8, 2, 14 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 8, 8, 14 14
2.5
µ=2.5
If there appears to be two medians, take the mean of the two
Median always has a percentile rank of 50% regardless of shape of distribution
Median also called the 2nd Quartile

29. Number of kids in family
1 4
3 2
1 8
4 2
2 14
Number of kids in family
1 3
1 4
2 4
2 8
2 14
How many kids are in your family?
What is the most common family size?
Median: The middle value when observations are
ordered from least to most (or most to least) 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 8, 14
Lower half
Upper half
2.5
2nd Quartile Middle number of all scores
(Median) 1, 1, 1, 1, 2, 2, 2, 3, 8, 14 2, 2, 3, 4, 4, 4, 2, 4, 4, 8, 14
1st Quartile
Middle number of lower half of scores
3rd Quartile
Middle number of upper half of scores

30. Number of kids in family
Mode: The value of the most frequent observation
Score f .
1 2
2 3
3 1
4 2
5 0
6 0
7 0
8 1
9 0
10 0
11 0
12 0
13 0
14 1
Number of kids in family
1 3
1 4
2 4
2 8
2 14
Please note:
The mode is “2” because it is the most frequently occurring score. It occurs “3” times. “3” is not the mode, it is just the frequency for the value that is the mode
Bimodal distribution:
If there are two most
frequent observations

31. What about central tendency for qualitative data?
Nominal data can only use the Mode
Ordinal data can use the Mode and Median (but not Mean)
Interval and Ratio data can use Mode, Median and Mean

32. Overview Frequency distributions
The normal curve
Challenge yourself as we work through characteristics of distributions to try to categorize each concept as a measure of
1) central tendency
2) dispersion or 3) shape
Mean, Median,
Mode, Trimmed Mean

33. Thank you!
See you next time!!