Geographic Data and Mapping Flashcards

Why might a U.S. city name appear as 'unknown' on a Tableau map even though the city exists?

Answer: The city name is ambiguous and needs a State/Province for disambiguation

Common city names exist in multiple states, so Tableau needs the State field to resolve them correctly.

Which mark type is automatically selected when Tableau first builds a map from a geographic field?

Answer: Map (filled) or Automatic, defaulting based on the geographic role

Tableau chooses a map-appropriate mark automatically based on the geographic role of the field used.

What is a common reason to use a background image (custom map) instead of Tableau's built-in maps?

Answer: To plot data on non-geographic layouts like a stadium, floor plan, or store map

Background images let you place X/Y data on custom layouts such as floor plans or seating charts.

When connecting to a spatial file, what special field does Tableau create to draw the geometry?

Answer: A Geometry field

Spatial connections generate a Geometry field containing the points, lines, or polygons to render.

How do you reduce overlapping marks (overplotting) on a dense point map in Tableau?

Answer: Switch to a Density (heatmap) mark or adjust opacity

Using the Density mark type or lowering mark opacity helps reveal patterns when many points overlap.

Which Tableau setting controls whether map data is rendered using an online map server or offline?

Answer: Map > Background Maps (Online, Offline, or Tableau)

The Background Maps menu lets you switch between Tableau's online maps, offline mode, or none.

What does setting a geographic field's role to 'None' accomplish?

Answer: It removes the geographic role so the field is treated as a normal dimension

Setting the role to None strips the geographic assignment, treating the field as an ordinary dimension.