1. Categorical vs. Quantitative Variables
4/17/2017
Categorical vs. Quantitative Variables
Identifying the Difference
4 Categorical vs. Quantitative.ppt

2. Variables Come in 2 Varieties
Categorical vs. Quantitative Variables
4/17/2017
Variables Come in 2 Varieties
Categorical (or __________)
Quantitative (or __________)
Categorical or Qualitative
Quantitative or Numerical
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

3. Categorical Variable Characteristics
Categorical vs. Quantitative Variables
4/17/2017
Categorical Variable Characteristics
Recorded usually with words
Records which of several groups an individual belongs to
Count data in each group, but you logically should not average it
Can calculate %age distributions
Includes all yes/no questions
Graphing: best illustrated with a pie chart
(but could also be a bar graph)
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

4. Quantitative Variable Characteristics
Categorical vs. Quantitative Variables
4/17/2017
Quantitative Variable Characteristics
Possible responses are numerical in nature
Includes values for which it makes sense to do operations like adding, totaling and averaging
Includes answers to how much/how many questions
Always includes ‘units’
Graphing: best illustrated with a bar chart
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

5. 2 Types of Quantitative Variables
Categorical vs. Quantitative Variables
2 Types of Quantitative Variables
4/17/2017
__________ If the Q variable is a set of isolated points on the
number line, we call it this (i.e., it’s a number but it only comes in certain values) Usually a variable that can be ‘counted’.
__________ If the Q variable forms an entire interval along the number line, we call it this. (i.e., it’s a number & it can be any value) Usually a variable that can be ‘measured’.
Discrete
Continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

6. Diagram of Variable Types
Introduction to Statistics--Variables

7. Categorical vs. Quantitative Variables
4/17/2017
Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete? Units?
Length of a pen?
Type of pen?
Number of pens in box?
Maker of pen?
Flow of ink in ml/sec?
Color of pen’s ink?
Point size of pen?
Subject of a book?
Number of pages in the book?
Area of each page of book?
Number of letters on a page?
Number of weeks on best seller list?
Quant; continuous
Categorical
Quant, discrete
Quant, continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

8. Categorical vs. Quantitative Variables
4/17/2017
Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete? Units?
Style of pants?
Color of pants?
Number of pairs of pants you own?
# of pockets on pants?
Size of pants?
Maker of the pants?
Length of inseam on the pants?
Quant; continuous
Categorical
Quant, discrete
Quant, continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

9. Reviewing Variable Types
Categorical vs. Quantitative Variables
4/17/2017
Reviewing Variable Types
__________ (or __________)
Categorical or Qualitative
Quantitative or Numerical
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

10. Reviewing ________ Variables
Categorical vs. Quantitative Variables
Reviewing ________ Variables
4/17/2017
Possible responses are ________ in nature
Includes values for which it makes sense to do operations like ________, ________ and ________.
Includes answers to ________/________ questions
Includes ‘________’
Usually—best illustrated with a ________, but
___________________________________.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

11. 2 Types of __________ Variables
Categorical vs. Quantitative Variables
4/17/2017
2 Types of __________ Variables
__________ If the Q variable forms an entire interval _______________, we call it this (i.e., it’s a number & it can be any value).
__________ If the Q variable is a set of isolated ___________ _________, we call it this (i.e., it’s a number but it only comes in certain values)
Discrete
Continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

12. Categorical vs. Quantitative Variables
4/17/2017
Classwork & Homework
Use the terms you’ve learned to analyze the types of variables you encounter in the samples
Answer some the ‘usual’ questions about the nature of this survey using the data and your powers of analysis.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

13. Answers to Fill in Blanks
Categorical vs. Quantitative Variables
4/17/2017
Answers to Fill in Blanks
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

14. Finding Individuals & Variables in a List
State
Region
Population
Males
Females
Alabama
Alaska
South
West
15.6m
5.4m
8.3m
2.5m
7.2m
2.9m
Arizona
10.2m
5.1m
Individuals in Sample—Usually in 1st Column
Variables—Usually in 2nd and succeeding columns
Number of in Sample = 3
Who’s in Sample?
Alabama, Alaska, Arizona
Variable = Region = Categorical
Variable = Population = Discrete Quantitative
Variable = Males = Discrete Quantitative
Variable = Females = Discrete Quantitative
Look for Variable Names in Column Headings
Introduction to Statistics--Variables

15. Variables Come in 2 Varieties
Categorical vs. Quantitative Variables
4/17/2017
Variables Come in 2 Varieties
Categorical (or Qualitative)
Quantitative (or Numerical)
Categorical or Qualitative
Quantitative or Numerical
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

16. 2 Types of Quantitative Variables
Categorical vs. Quantitative Variables
4/17/2017
2 Types of Quantitative Variables
Discrete If the Q variable is a set of isolated points on the
number line, we call it this (i.e., it’s a number but it only comes in certain values)
Continuous If the Q variable forms an entire interval along the number line, we call it this (i.e., it’s a number & it can be any value).
Discrete
Continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

17. Categorical vs. Quantitative Variables
4/17/2017
Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete?
Length of a pen?
Type of pen?
Number of pens in box?
Maker of pen?
Flow of ink in ml/sec?
Color of pen’s ink?
Quantitative, Continuous
Categorical
Quantitative, Discrete
Quant; continuous
Categorical
Quant, discrete
Quant, continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

18. Categorical vs. Quantitative Variables
4/17/2017
Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete?
Subject of a book?
Number of pages in the book?
Area of each page of book?
Number of letters on a page?
Number of weeks on best seller list?
Categorical
Quantitative, Discrete
Quantitative, Continuous
Quantitaitve, Discrete
Quant; continuous
Categorical
Quant, discrete
Quant, continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

19. Categorical vs. Quantitative Variables
4/17/2017
Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete?
Style of pants?
Color of pants?
Number of pairs of pants you own?
# of pockets on pants?
Size of pants?
Maker of the pants?
Length of inseam on the pants?
Categorical
Quantitative, Discrete
Quantitative, Continuous
Quant; continuous
Categorical
Quant, discrete
Quant, continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

20. Reviewing Variable Types
Categorical vs. Quantitative Variables
4/17/2017
Reviewing Variable Types
Categorical (or Qualitative)
Quantitative (or Numerical)
Categorical or Qualitative
Quantitative or Numerical
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

21. Reviewing Quantitative Variables
Categorical vs. Quantitative Variables
Reviewing Quantitative Variables
4/17/2017
Possible responses are numerical in nature
Includes values for which it makes sense to do operations like adding, totaling and averaging.
Includes answers to how much/how many questions
Includes ‘units’
Usually—best illustrated with a bar graph, but
pie chart is also possible.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

22. Reviewing Categorical Variables
Categorical vs. Quantitative Variables
4/17/2017
Reviewing Categorical Variables
Recorded usually with words
Records which of several categories an individual belongs to
Count data in each group, but you logically should not average it
Can calculate percentage distributions
Includes all yes/no questions
Usually—best illustrated with a pie chart.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

23. 2 Types of Quantitative Variables
Categorical vs. Quantitative Variables
4/17/2017
2 Types of Quantitative Variables
Continuous If the Q variable forms an entire interval along the number line, we call it this (i.e., it’s a number & it can be any value).
2. Discrete If the Q variable is a set of isolated points on the
number line, we call it this (i.e., it’s a number but it only comes in certain values)
Discrete
Continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt