Analytics-DA-201 - Explore and Analyze Data (41% of the exam) - Section 2.7
Create symbol maps, density maps, and choropleth (filled) maps, and add mark layers.
Practice question for this objective
lock_openFree sampleExplore and Analyze Datamedium
An analyst has a filled map of council areas shaded by recycling rate and wants to add a second mark layer showing depot locations as points on the same map. They open the Marks card menu but find no option to add a layer. The view currently builds its map from a single pair of generated coordinate fields on Rows and Columns. What must be present for the Add Mark Layer option to become available?
AA second geographic field dragged onto the map pane so Tableau can place it as a new layercheck_circle Correct
BA dual-axis configuration applied to the two generated latitude fields on the Rows shelf
CA blend between two separate data sources joined on a common region key
DA conversion of the recycling-rate measure into a discrete dimension first
Add a mark layer by dropping a second geographic field onto the map canvas to overlay distinct encodings. Mark layering is driven by placing an additional geographic field onto the map pane, which creates a separate layer with its own marks card so polygons and points can coexist.
Why A is correct: Dropping another geographic field onto the map canvas creates an additional mark layer, which is the action that exposes and uses the layering capability.
Why B is wrong: Dual axis with two latitude pills is the older technique for overlaying marks, but it is not what enables the modern Add Mark Layer option, which works by dropping a geographic field onto the canvas.
Why C is wrong: Data blending is unrelated to map layering, so configuring a blend would not produce the Add Mark Layer option for points on the same map.
Why D is wrong: Changing the measure to discrete affects how the existing layer is shaded, not whether a new mark layer can be added, so it does not solve the problem.
Answers that look right on this material and are not. Each one is a distractor from a different question in the Analytics-DA-201 bank for this domain.
Add a second copy of the Income measure to the Size shelf
errorWhy it is wrong: Sizing marks by income would scale point circles, which keeps the point mark type and does not turn the states into filled polygons.
Symbol maps automatically normalise the measure by area, removing the influence of how large each region is.
errorWhy it is wrong: Tableau does not normalise the measure by area for symbol maps; any per-area adjustment must be calculated by the analyst, so this overstates what the map type does.
The Sales measure must be placed on the Detail shelf rather than on Colour
errorWhy it is wrong: Placing the measure on Detail would prevent the shading that defines a choropleth; the colour encoding is what conveys the value, so this would produce uniform polygons rather than a filled map.