Data Tools and Visualization Flashcards

Which chart type is best for displaying the distribution of a single continuous variable?

Answer: Histogram

A histogram bins a continuous variable to show its frequency distribution.

In Tableau, what is the difference between a live connection and an extract?

Answer: Live queries the source directly; extract is a static in-memory snapshot

A live connection queries the source in real time, while an extract is a saved snapshot.

What is the recommended maximum number of slices before a pie chart becomes hard to read?

Answer: Around 5-6 slices

Pie charts become unreadable beyond roughly five or six slices.

In SQL for reporting, which clause groups rows so aggregate functions apply per category?

Answer: GROUP BY

GROUP BY groups rows by column values so aggregates compute per group.

Which principle suggests placing the most important dashboard metric in the top-left area?

Answer: Z-pattern / F-pattern reading flow

Western readers scan in Z/F patterns, so key metrics belong top-left.

A choropleth map encodes data values using what visual attribute?

Answer: Color shading of geographic regions

A choropleth shades geographic regions by their data value.

In Power BI or Tableau, what is the main benefit of drill-down functionality?

Answer: Letting users navigate from summary to detailed levels

Drill-down lets users move from aggregated summaries into finer detail.