MS-DS Master of Data science Data Visualization and Communication 5

Question 1

In Tableau, what is the difference between a 'dimension' and a 'measure' by default?

Accepted Answer

Dimensions are categorical fields used for grouping/slicing; measures are numeric fields that are aggregated

Answer

Tableau classifies discrete categorical fields as dimensions (used to partition data) and continuous numeric fields as measures (aggregated via SUM, AVG, etc.).

Question 2

A scatter plot shows a strong visual correlation between ice cream sales and drowning rates. What concept does this best illustrate in data communication?

Accepted Answer

Confounding — a lurking variable (hot weather) drives both

Answer

Both variables are driven by a common cause (summer heat), making them spuriously correlated — a classic confounding example used in data literacy education.

Question 3

Which perceptual ranking (from most to least accurate) correctly reflects Cleveland and McGill's hierarchy for quantitative judgments?

Accepted Answer

Position on common scale → length → angle → area

Answer

Cleveland & McGill's 1984 experiments found that people most accurately judge position on a common scale, then length, then angle, with area and color being least accurate.

Question 4

What does 'progressive disclosure' mean in the context of interactive data dashboards?

Accepted Answer

Revealing detail on demand (drill-down, tooltip, filter) rather than showing everything at once

Answer

Progressive disclosure keeps dashboards uncluttered by showing summary information upfront and allowing users to access deeper detail only when they request it.

Question 5

A radar (spider) chart is generally considered problematic for data communication. Which is the primary reason?

Accepted Answer

Area perception is non-linear and axis order arbitrarily affects the polygon shape, making comparison difficult

Answer

Reordering the axes changes the polygon shape even with identical data, and humans poorly judge areas of irregular polygons, making radar charts prone to misinterpretation.

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Data Visualization and Communication 5