Data Visualization and Communication Flashcards
7 cards from real MS-DS Master of Data science practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Data Visualization and Communication flashcards as text
In Tableau, what is the difference between a 'dimension' and a 'measure' by default?
Answer: Dimensions are categorical fields used for grouping/slicing; measures are numeric fields that are aggregated
Tableau classifies discrete categorical fields as dimensions (used to partition data) and continuous numeric fields as measures (aggregated via SUM, AVG, etc.).
A scatter plot shows a strong visual correlation between ice cream sales and drowning rates. What concept does this best illustrate in data communication?
Answer: Confounding — a lurking variable (hot weather) drives both
Both variables are driven by a common cause (summer heat), making them spuriously correlated — a classic confounding example used in data literacy education.
Which perceptual ranking (from most to least accurate) correctly reflects Cleveland and McGill's hierarchy for quantitative judgments?
Answer: Position on common scale → length → angle → area
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.
What does 'progressive disclosure' mean in the context of interactive data dashboards?
Answer: Revealing detail on demand (drill-down, tooltip, filter) rather than showing everything at once
Progressive disclosure keeps dashboards uncluttered by showing summary information upfront and allowing users to access deeper detail only when they request it.
A radar (spider) chart is generally considered problematic for data communication. Which is the primary reason?
Answer: Area perception is non-linear and axis order arbitrarily affects the polygon shape, making comparison difficult
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.
When applying the 'SIFT' framework for evaluating data sources before visualizing them, what does the 'I' stand for?
Answer: Investigate the source
SIFT (Stop, Investigate the source, Find better coverage, Trace claims) is a media literacy framework; 'I' means investigating who produced the data and why.
In accessible data visualization, what is the purpose of providing an 'alt text' description alongside a chart image?
Answer: To convey the chart's key insight to screen-reader users who cannot see the image
Alt text for charts should describe the type of chart and its key finding so blind and low-vision users consuming the page via screen readers receive equivalent information.