Part I Yippee! I’m in Statistics Chapter 1 Statistics or Sadistics?: It’s Up to You.
Post on 05-Jan-2016
213 Views
Preview:
Transcript
Part IYippee! I’m in Statistics
Chapter 1 Statistics or Sadistics?: It’s Up to You
Why Statistics? Statistics for People Who (Think They) Hate
Statistics Follows an approach that is:
Un-intimidating Informative Applied Even a little fun!
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
Statistics: What It Is (and Isn’t) 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
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
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!!
Success in this Course A few hints for successful completion of this course
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 VERY Hard Hard Not too hard, but not too easy Easy VERY Easy
Glossary Terms to Know Descriptive statistics
Data or data set Inferential statistics
Population Sample
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.
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.
Now You Try! 2+5*X 2+(3-1) * 32
5- (10)2 /50 Sqrt [ 5(8) – (4)2 ] [ 3(6) –(3)2 ]
Chapter 1 14
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
Chapter 1 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
Chapter 1 16
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.
Chapter 1 17
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
Chapter 1 18
Learning a new languageMeasurement scales: Ordinal
Ordinal scales What is measured is placed in groups by a ranking
1st, 2nd, 3rd
Chapter 1 19
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
1st place 2nd place 3rd place
Time
Chapter 1 20
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
Chapter 1 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
0 +10 +20-20 -10
top related