MS-DS Master of Data science Data Visualization and Communication 2

Question 1

Which color encoding principle states that hue should be used for nominal data while luminance/saturation should encode ordered data?

Accepted Answer

Bertin's retinal variables principle

Answer

Jacques Bertin established that hue differentiates categories (nominal), while value/lightness encodes order or quantity (ordinal/quantitative).

Question 2

A dashboard shows a KPI card with a large number and no trend context. What is the primary communication failure?

Accepted Answer

Absence of a reference baseline or comparison

Answer

A single number without a baseline, target, or historical trend gives the viewer no way to judge whether the value is good or bad.

Question 3

When visualizing a distribution with heavy outliers, which chart type preserves the most information without distortion?

Accepted Answer

Box-and-whisker plot

Answer

A box-and-whisker plot explicitly shows median, IQR, whiskers, and individual outlier points without collapsing the distribution into a single mean.

Question 4

The 'lie factor' metric introduced by Edward Tufte measures what?

Accepted Answer

The ratio of the effect size shown in the graphic to the effect size in the data

Answer

Tufte defined Lie Factor = (size of effect shown in graphic) / (size of effect in data); a value far from 1.0 indicates visual distortion.

Question 5

In a connected scatterplot (path chart), what does the path between points encode that a standard scatterplot omits?

Accepted Answer

Temporal sequence or ordering

Answer

The path connects observations in order (usually time), revealing how two variables co-evolved — information a static scatterplot cannot convey.

MS-DS Master of Data science Practice Test