Part I Yippee! I

1
Part IYippee! Im in Statistics

• Chapter 1 ? ? ? ? ?
• Statistics or Sadistics? Its Up to You

2
Why Statistics?

• Statistics for People Who (Think They) Hate
  Statistics
• Follows an approach that is
• Un-intimidating
• Informative
• Applied
• Even a little fun!

3
A Five-Minute History

• 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
• Agriculture
• Astronomy
• Politics

4
Statistics What It Is (and Isnt)

• 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
• Collect
• Organize
• Summarize
• Interpret

5
Descriptive or Inferential?

• What is Descriptive Statistics?
• Used to organize and describe the characteristics
  of a particular data set
• Example the average age of everyone in this
  class!
• What is Inferential Statistics?
• Used to make inferences from your sample to the
  population
• Example comparing the mean age of students
  taking this course to average age of all students
  in an introductory statistics course

6
Why Statistics is Important

• Understanding basic statistics will help you in
  the following ways
• 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!!

7
Success in this Course

• A few hints for successful completion of this
  course
• Youre not dumb
• How do you know statistics is hard?
• Dont 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!!

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About Those Icons
9
Key to Difficulty Index

• VERY Hard ?
• Hard ? ?
• Not too hard, but not too easy ? ? ?
• Easy ? ? ? ?
• VERY Easy ? ? ? ? ?

10
Glossary Terms to Know

• Descriptive statistics
• Data or data set
• Inferential statistics
• Population
• Sample

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Algebraic Order

• 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.

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PEMDAS

• 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.

13
Now You Try!

• 25X
• 2(3-1) 32
• 5- (10)2 /50
• Sqrt 5(8) (4)2 3(6) (3)2

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Learning a new languageTypes of variables

• How it can be measured matters
• Discrete variables
• What is measured belongs to unique and separate
  categories
• Pets dog, cat, goldfish, rats
• If there are only two categories, then it is
  called a dichotomous variable
• Open or closed male or female

15
Learning a new languageTypes of variables

• Continuous variables
• What is measured varies along a line scale and
  can have small or large units of measure
• Length
• Temperature
• Age
• Distance
• Time

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Learning a new languageMeasurement scales
Nominal

• Measurement scales
• Nominal scales
• Separated into different categories
• All categories are equal
• Cats, dogs, rats
• NOT 1st, 2nd, 3rd
• There is no magnitude within a category
• One dog is not more dog than another.

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Learning a new languageMeasurement scales
Nominal

• No intermittent categories
• No dog/cat or cat/fish categories
• Membership in only one category, not both
• Mutually exclusive properties

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Learning a new languageMeasurement scales
Ordinal

• Ordinal scales
• What is measured is placed in groups by a ranking
• 1st, 2nd, 3rd

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Learning a new languageMeasurement scales
Ordinal

• Although there is a ranking difference between
  the groups, the actual difference between the
  group may vary.
• Marathon runners classified by finish order
• The times for each group will be different
• Top ten 4- to 5-hour times
• Bottom ten 4- to 5-week times

Time
1st place
2nd place
3rd place
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Learning a new languageMeasurement scales
Interval

• Interval scales
• 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.
• Height
• Speed

Length
21
Learning a new languageMeasurement scales

• Ratio scale
• Just like an interval scale, and there is a
  definable and reasonable zero point.
• Time, weight, length
• Seldom used in social sciences
• All ratio scales are also interval scales, but
  not all interval scales are ratio scales

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