Data Visualization Color Theory and Visual Encoding 3

Question 1

What is 'data-ink ratio' as defined by Edward Tufte?

Accepted Answer

The proportion of ink devoted to displaying non-redundant data

Answer

Tufte's data-ink ratio is the fraction of ink used to represent actual data versus total ink used; maximizing it reduces chart junk.

Question 2

What is 'chartjunk' according to Edward Tufte?

Accepted Answer

Unnecessary visual elements that do not convey information

Answer

Chartjunk refers to decorative or redundant visual elements—gridlines, 3D effects, clipart—that clutter charts without adding informational value.

Question 3

Which principle suggests that visual elements encoding the same variable should be perceptually uniform?

Accepted Answer

Perceptual linearity

Answer

Perceptual linearity ensures that equal data differences appear as equal visual differences (e.g., perceptually uniform color scales like viridis).

Question 4

What visual encoding principle states that elements close together are perceived as belonging to the same group?

Accepted Answer

Proximity

Answer

The Gestalt principle of proximity states that spatially close elements are automatically perceived as grouped together.

Question 5

Why should pie charts avoid using more than 5–6 slices?

Accepted Answer

Humans struggle to accurately compare small angles and thin slices

Answer

Humans are poor at judging small angle differences, making thin pie slices nearly impossible to compare accurately.

Data Visualization Practice Test