Part I
Yippee! I’m in Statistics
Chapter 1     
Statistics or Sadistics?: It’s Up to You
Why Statistics?
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Statistics for People Who (Think They) Hate
Statistics
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Follows an approach that is:
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Un-intimidating
Informative
Applied
Even a little fun!
A Five-Minute History
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17th century the first set of data pertaining to
populations was collected
Need arose to develop specific tools to help
answer specific questions
Basic statistical procedures were developed in
the fields of
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Agriculture
Astronomy
Politics
Statistics: What It Is (and Isn’t)
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Statistics describes “a set of tools and
techniques that is used for describing,
organizing, and interpreting data.”
The text will help you learn how to do the
following with data:
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Collect
Organize
Summarize
Interpret
Descriptive or Inferential?
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What is Descriptive Statistics?
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Used to organize and describe the characteristics
of a particular data set
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Example: the average age of everyone in this class!
What is Inferential Statistics?
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Used to make inferences from your “sample” to
the “population”
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Example: comparing the mean age of students taking
this course to average age of all students in an
introductory statistics course
Why Statistics is Important
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Understanding basic statistics will help you in
the following ways:
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Better prepare you for advance courses (both
undergraduate or graduate)
Sets you apart from those who do not take
courses in statistics
Challenges you intellectually
Makes you a better student in the behavioral or
social sciences!!
Success in this Course
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A few hints for successful completion of this course
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You’re not dumb
How do you know statistics is hard?
Don’t skip lessons!!
Form a study group
Ask questions
Work through the exercises in each chapter
Practice, Practice, Practice
Look for real-world applications
Browse
HAVE FUN!!
About Those Icons
Key to Difficulty Index
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VERY Hard 
Hard  
Not too hard, but not too easy   
Easy    
VERY Easy     
Glossary Terms to Know
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Descriptive statistics
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Data or data set
Inferential statistics
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Population
Sample
Algebraic Order
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Parentheses and Brackets -- Simplify the inside of parentheses
and brackets before you deal with the exponent (if any) of the set
of parentheses or remove the parentheses.
Exponents -- Simplify the exponent of a number or of a set of
parentheses before you multiply, divide, add, or subtract it.
Multiplication and Division -- Simplify multiplication and
division in the order that they appear from left to right.
Addition and Subtraction -- Simplify addition and subtraction in
the order that they appear from left to right.
PEMDAS
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Important: It is not correct to say that we
must always do addition before subtraction,
because A comes before S in PEMDAS
For example: 4 - 1 + 7 - 2. We get 8 working
left to right
Another example: 5 x 6 ÷ 2 ÷ 5. We get 3
working left to right.
Now You Try!
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2+5*X
2+(3-1) * 32
5- (10)2 /50
Sqrt [ 5(8) – (4)2 ] [ 3(6) –(3)2 ]
Learning a new language
Types of variables
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How it can be measured matters
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Discrete variables
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What is measured belongs to unique and separate
categories
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If there are only two categories, then it is called a
dichotomous variable
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Chapter 1
Pets: dog, cat, goldfish, rats
Open or closed; male or female
14
Learning a new language
Types of variables
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Continuous variables
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What is measured varies along a line scale and can
have small or large units of measure
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Chapter 1
Length
Temperature
Age
Distance
Time
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Learning a new language
Measurement scales: Nominal
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Measurement scales
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Nominal scales
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Separated into different categories
All categories are equal
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There is no magnitude within a category
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Chapter 1
Cats, dogs, rats
NOT: 1st, 2nd, 3rd
One dog is not more dog than another.
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Learning a new language
Measurement scales: Nominal
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No intermittent categories
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Chapter 1
No dog/cat or cat/fish categories
Membership in only one category, not both
Mutually exclusive properties
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Learning a new language
Measurement scales: Ordinal
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Ordinal scales
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What is measured is placed in groups by a ranking
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Chapter 1
1st, 2nd, 3rd
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Learning a new language
Measurement scales: Ordinal
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Although there is a ranking difference between the
groups, the actual difference between the group may
vary.
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Marathon runners classified by finish order
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The times for each group will be different
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Top ten 4- to 5-hour times
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Bottom ten 4- to 5-week times
Time
1st place
Chapter 1
2nd place
3rd place
19
Learning a new language
Measurement scales: Interval
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Interval scales
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Someone or thing is measured on a scale in which
interpretations can be made by knowing the resulting
measure.
The difference between units of measure is consistent.
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Height
Speed
Length
Chapter 1
20
Learning a new language
Measurement scales
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Ratio scale
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Just like an interval scale, and there is a definable and
reasonable zero point.
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Time, weight, length
-20
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Chapter 1
-10
0
+10
+20
Seldom used in social sciences
All ratio scales are also interval scales, but not all
interval scales are ratio scales
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