1. Categorical vs. Quantitative Variables
2/5/2019
Categorical vs. Quantitative Variables
Identifying the Difference
4 Categorical vs. Quantitative.ppt

2. How do the items on the left side compare with the items on the right?
Categorical
Quantitative
Favorite Color
Hourly wage
Sports Team
Number of Siblings
Subject in School
Time spent studying
Type of car you drive
Shoe size
Introduction to Statistics--Variables

3. Variables Come in 2 Varieties
Categorical vs. Quantitative Variables
2/5/2019
Variables Come in 2 Varieties
Categorical (or __________)
Quantitative (or __________)
Categorical or Qualitative
Quantitative or Numerical
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

4. Categorical Variables
Categorical vs. Quantitative Variables
2/5/2019
Categorical Variables
Recorded usually with _______
Records which of several __________ an individual belongs to
Count data in each ________, but you logically should not __________ it
Can calculate ___________ distributions
Includes all _________ questions
Usually—best illustrated with a ________ _____________.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

5. Quantitative Variables
Categorical vs. Quantitative Variables
Quantitative Variables
2/5/2019
Possible responses are ___________ in nature
Includes values for which it makes sense to do operations like _________ and ___________.
Includes answers to _________________ questions
Includes _______
Illustrated with graphs like __________, ____________, ____________, & _________.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

6. Introduction to Statistics--Variables
FYI
Just because you have a number, doesn't necessarily make it quantitative.
For example:
___________
… all _______, but it doesn't make much sense to find the or _______ _________.
*These are examples of __________ applied to __________________.
Introduction to Statistics--Variables

7. Qualitative vs Quantitative Data
Overview:
Qualitative vs Quantitative Data
Qualitative Data
Deals with descriptions.
Data can be observed but not measured.
Colors, textures, smells, tastes, appearance, beauty, etc.
Qualitative → Quality
Quantitative Data
Deals with numbers.
Data which can be measured.
Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc.
Quantitative → Quantity

8. Categorical or Quantitative?
Categorical vs. Quantitative Variables
2/5/2019
Categorical or Quantitative?
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

9. Categorical or Quantitative?
Categorical vs. Quantitative Variables
2/5/2019
Categorical or Quantitative?
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

10. Determine if each Variable is Categorical or Quantitative
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
Look for Variable Names in Column Headings
Variable = State =
Variable = Region =
Variable = Population =
Variable = Males =
Variable = Females =
Categorical
Quantitative
Introduction to Statistics--Variables

11. Provide a Qualitative & Quantitative Description of the Image
Example 1: Oil Painting
Qualitative data:
Quantitative data:

12. Provide a Qualitative & Quantitative Description of the Image
Example 2: Latte
Qualitative data:
Quantitative data:

13. Provide a Qualitative & Quantitative Description of the Image
Example 3: Freshman Class
Qualitative data:
Quantitative data:

14. Make one qualitative observation about the picture above.
Explain why this is a qualitative observation.
Make one quantitative observation about the picture above.
Explain why this is a quantitative observation.

15. Make one qualitative observation about the picture above.
Explain why this is a qualitative observation.
Make one quantitative observation about the picture above.
Explain why this is a quantitative observation.

16. Variables Come in 2 Varieties
Categorical vs. Quantitative Variables
2/5/2019
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

17. Categorical Variables
Categorical vs. Quantitative Variables
2/5/2019
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 or bar graph.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

18. Quantitative Variables
Categorical vs. Quantitative Variables
Quantitative Variables
2/5/2019
Possible responses are numerical in nature
Includes values for which it makes sense to do operations like adding and averaging.
Includes answers to how much/how many questions
Includes units
Illustrated with graphs like stem and leaf,
box plots, histograms, & scatter plots.
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

19. 2 Types of Quantitative Variables
Categorical vs. Quantitative Variables
2/5/2019
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

20. Introduction to Statistics--Variables
FYI
Just because you have a number, doesn't necessarily make it quantitative.
For example:
zip codes
phone numbers
bank-accounts
… all numeric, but it doesn't make much sense to find the average phone number or median zip-code.
*These are examples of numbers applied to categorical data.
Introduction to Statistics--Variables

21. Categorical vs. Quantitative Variables
2/5/2019
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

22. Categorical vs. Quantitative Variables
2/5/2019
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
Quant; continuous
Categorical
Quant, discrete
Quant, continuous
Introduction to Statistics--Variables
4 Categorical vs. Quantitative.ppt

23. Categorical vs. Quantitative Variables
2/5/2019
Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete?
Categorical
Quantitative, Discrete
Quantitative, Continuous
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

24. Provide a Qualitative & Quantitative Description of the Image
Example 1: Oil Painting
Qualitative data:
(Possible responses)
*red/green color, gold frame
*smells old and musty
*texture shows brush strokes of oil paint
*peaceful scene of the country
*masterful brush strokes
Quantitative data:
*picture is 10" by 14”
with frame 14" by 18”
* weighs 8.5 pounds
surface area of painting is 140 sq. in.
*cost $300

25. Provide a Qualitative & Quantitative Description of the Image
Example 2: Latte
Qualitative data:
(Possible responses)
*robust aroma
*frothy appearance
* strong taste
*glass cup
Quantitative data:
*12 ounces of latte
*serving temperature 1500 F.
*serving cup 7 inches in height
*cost $4.95

26. Provide a Qualitative & Quantitative Description of the Image
Example 3: Freshman Class
Qualitative data:
(Possible responses)
*friendly demeanors
*civic minded
*environmentalists
*positive school spirit
Quantitative data:
*672 students
*394 girls, 278 boys
*68% on honor roll
*150 students accelerated in mathematics

27. Make one qualitative observation about the picture above.
Explain why this is a qualitative observation.
Make one quantitative observation about the picture above.
Explain why this is a quantitative observation.

28. Make one qualitative observation about the picture above.
Explain why this is a qualitative observation.
Make one quantitative observation about the picture above.
Explain why this is a quantitative observation.