Chapter 4

Question 1

What are the methods to visualise a single categorical variable?

Answer 1

Frequency Distribution
Bar chart

Question 2

What are the methods to visualise a single numerical variable?

Answer 2

Frequency distribution
Histogram

Question 3

Which guidelines can be followed to make decisions of intervals as well as the width of each of each interval?

Answer 3

1. Intervals are mutually exclusive
2. Intervals are exhaustive
3. The total number of intervals in a frequency distribution usually ranges from 5 to 20
4. Interval limits are easy to recognise and interpret

Question 4

What are some guidelines a researcher can follow when constructing and interpreting charts or graphs?

Answer 4

1. Simplest graph should be used for a given set of data. Strive for clarity and avoid unnecessary endorsements
2. Axes should be marked with the number of their respective scales, each axis should be labeled
3. Each bar should be the same width to avoid distortion
4. Vertical axis should not be given a very high value as an upper limit
5. Vertical axis should not be stretched

Question 5

What are methods to visualise the relationship between 2 categorical variables?

Answer 5

Contingency table
Stacked column chart

Question 6

What are methods to visualise the relationship between 2 numerical variables?

Answer 6

Scatterplot

Question 7

What are other visualisation methods?

Answer 7

• scatterplot (with categorical variables)
• bubble plot
• line chart
• heatmap
• dashboard