1. Lecture 2 Chapter 2. Displaying and Describing Categorical Data
Week 1
Lecture 2 Chapter 2. Displaying and Describing Categorical Data

2. Distribution of Perceived Health (2012) Canadian Community Health Survey (CCHS)
Graphical displays of a categorical data:
Bar chart
Pie chart

3. Distribution of Perceived Health (2012) Canadian Community Health Survey (CCHS)
Variable(s): 2
Variable Names: Perceived Health, Sex
Variable Type:
Perceived Health: Ordinal Categorical Variable
0 = Poor, 1 = Fair, 2 = Good, 3 = Very Good, 4 = Excellent
Sex: Nominal Categorical Variable
Male, Female
StatCrunch:
Stat>Tables>Contingency>With Data
Row Variable: perceived health
Column Variable: sex
Compute!
Most females and males reported “Very Good” as their perceived health.

4. Graph: Bar Chart (Perceived Health By Sex)

5. Graph: Bar Chart (Perceived Health By Sex)
StatCrunch:
Graph>Bar Plot>With Data
Select Column: perceived health
Group By: Sex
Grouping Option:
Separate graphs for each group
Compute!
Most females and males reported “3 = Very Good” as their perceived health.

6. Graph: Pie Chart (Perceived Health By Sex)
StatCrunch:
Graph>Pie Chart>With Data
Select Column: perceived health
Group By: Sex
Compute!
Again, not much difference is apparent. It is better to construct a bar chart for each sex group, but put bars side by side (on the next slide).

7. Graph: Clustered Bar Chart (Perceived Health By Sex)
StatCrunch:
Stat>Tables>Contingency>With Data
Row Variable: sex
Column Variable: perceived health
Compute!
StatCrunch:
Graph>Bar Plot>With Data
Select Column: perceived health
Group By: Sex
Compute!

8. Contingency Table of Perceived Health By Sex Reading the Table
There were 1500 respondents.
832 of the respondents were female.
315 of the respondents were female who reported “3 = Vey Good” as their perceived health.
240 of the respondents were male who reported
“3 = Very Good” as their perceived health.

9. Contingency Table of Perceived Health By Sex Marginal Distribution
Marginal Distribution of Sex:
For example,
What percentage of the respondents were male?
Marginal Distribution of Perceived Health:
What percentage of the respondents reported
“3 = Very Good” as their perceived health?

10. Contingency Table of Perceived Health By Sex Marginal Distribution
Marginal Distribution of Sex:
For example,
What percentage of the respondents were male?
𝟔𝟔𝟖 𝟏𝟓𝟎𝟎 = x 100 = 44.53%
Marginal Distribution of Perceived Health:
What percentage of the respondents reported
“3 = Very Good” as their perceived health?
𝟓𝟓𝟓 𝟏𝟓𝟎𝟎 = 0.37 x 100 = 37%

11. Contingency Table of Perceived Health By Sex Conditional Distribution
Row Percentages:
For example,
What percentage of the females reported “3 = Very Good” as their perceived health?

12. Contingency Table of Perceived Health By Sex Conditional Distribution
Row Percentages (of Row Total):
For example,
What percentage of the females reported “3 = Very Good” as their perceived health?
𝟑𝟏𝟓 𝟖𝟑𝟐 = x 100 = 37.86%

13. Contingency Table of Perceived Health By Sex Conditional Distribution
Column Percentages:
For example,
What percentage of those who reported
“3 = Very Good” as their perceived health were females?

14. Contingency Table of Perceived Health By Sex Conditional Distribution
Column Percentages (of Column Total):
For example,
What percentage of those who reported
“3 = Very Good” as their perceived health were females?
𝟑𝟏𝟓 𝟓𝟓𝟓 = x 100 = 56.76%

15. Contingency Table of Perceived Health By Sex Conditional Distribution
Joint Distribution:
For example,
What percentage of respondents were female and reported “3 = Very Good” as their perceived health?

16. Contingency Table of Perceived Health By Sex Conditional Distribution
Joint Distribution (Out of Everything):
For example,
What percentage of respondents were female and reported “3 = Very Good” as their perceived health?
𝟑𝟏𝟓 𝟏𝟓𝟎𝟎 = 0.21 x 100 = 21%