Data Science Data Visualization and Communication 2 — Questions and Answers
Question 1: Which chart type is most appropriate for showing the part-to-whole composition of a single category at one point in time?
- Line chart
- Pie chart (Correct answer)
- Scatter plot
- Box plot
Correct answer: Pie chart
A pie chart shows how parts make up a whole for a single categorical breakdown.
Question 2: You want to compare the distribution and outliers of salaries across five departments. Which visualization is best?
- Stacked bar chart
- Box plot (Correct answer)
- Pie chart
- Single line chart
Correct answer: Box plot
A box plot summarizes median, quartiles, and outliers across multiple groups for easy comparison.
Question 3: Which color palette is most appropriate for a diverging metric like temperature anomaly centered on zero?
- Sequential single-hue palette
- Diverging two-hue palette (Correct answer)
- Qualitative categorical palette
- Random rainbow palette
Correct answer: Diverging two-hue palette
Diverging palettes use two contrasting hues around a meaningful midpoint to show deviation in both directions.
Question 4: What is the main reason to avoid truncating the y-axis (not starting at zero) on a bar chart?
- It makes the chart load slower
- It can exaggerate differences and mislead viewers (Correct answer)
- It removes the legend
- It changes the underlying data
Correct answer: It can exaggerate differences and mislead viewers
Truncated axes on bar charts visually exaggerate small differences, misleading the audience.
Question 5: Which visualization best reveals the correlation between two continuous variables across many observations?
- Pie chart
- Scatter plot (Correct answer)
- Stacked area chart
- Donut chart
Correct answer: Scatter plot
A scatter plot maps two continuous variables to axes, revealing correlation and clustering patterns.
Question 6: When presenting results to a non-technical executive audience, what should you lead with?
- The raw model coefficients
- The key takeaway and its business impact (Correct answer)
- The data cleaning steps
- The full code repository
Correct answer: The key takeaway and its business impact
Executives need the actionable insight and impact first, with technical detail available on request.
Question 7: What does the principle of 'data-ink ratio' (Tufte) recommend?
- Add more decorative gridlines and 3D effects
- Maximize ink used for non-data elements
- Maximize the proportion of ink devoted to displaying actual data (Correct answer)
- Use as many colors as possible
Correct answer: Maximize the proportion of ink devoted to displaying actual data
Tufte advises maximizing data-ink and removing redundant chart junk that doesn't convey information.
Data Science Data Visualization and Communication 2
Which chart type is most appropriate for showing the part-to-whole composition of a single category at one point in time?