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Canonical: https://semiotic.nteract.io/examples/data-viz-for-dummies-5
Data Viz for Dummies V
The road season · geography joins the scouting report
A map is a chart only when location changes the answer.
Parts I through IV completed the core roster. Part V leaves the arena and asks what happens when adjacency, distance, direction, or street context becomes data. Six geo formations show when the map earns its minutes—and when geography is just expensive wallpaper.
6 geo formations6 location contracts0 decorative maps
GEO 501RC · 2026
05THE ROAD MAP
Where · how far · which way
100Place
98Route
95Scale
00Globe
00
Map room · location must do analytical work
Before choosing a map, name the geographic relationship the reader needs.
Geo charts encode more than coordinates. Regions imply adjacency, symbols preserve exact locations, flows add direction, cartograms redefine distance, tiles provide navigational context, and custom layouts preserve projection while changing the visible grammar.
COACH’S CHALLENGEIf the conclusion would survive after replacing every place name with A, B, and C, geography may not be carrying the argument. Try a bar chart before reaching for an atlas.
Six-map travel roster
Every formation answers a different version of ‘where?’
Read the data contract before the chart name. Area, point, edge, cost, street, and custom geometry are not interchangeable geographic ingredients.01regions + one rate
Choropleth
compare values attached to areas
large land areas dominate attention02coordinates + magnitude
Proportional symbol
compare located totals
overlap hides small neighbors03places + directed connections
Flow map
show movement between locations
routes become spaghetti04places + cost from an origin
Distance cartogram
replace miles with experienced distance
geographic position is deliberately broken05precise coordinates + local context
Tiled map
support street-level orientation
basemap detail can overpower the data06projected data + a bespoke layout
Geo custom
invent geography-aware geometry
the metaphor must remain navigable 01
Choropleth · regional scouting
Color the area only when the value belongs to the area.
Choropleths bind one numeric measure to each geographic feature. They excel at rates, shares, and normalized measures whose meaning is regional. Adjacency and broad spatial clusters become visible immediately.
COACH’S CHALLENGERaw totals reward populous or large regions twice: once in the number and again in visual area. Normalize when exposure differs, and never let missing data masquerade as zero.
02
Proportional symbol · the scouting circuit
Keep the place fixed and let magnitude change the mark.
Proportional symbols place a circle at each coordinate and scale its radius from a measure. Unlike a choropleth, the value belongs to a site rather than the surrounding land. Color can add a categorical region without repainting the world.
COACH’S CHALLENGEArea is compared imprecisely, and large circles can cover smaller neighbors. Use restrained size ranges, transparency, and tooltips—and cluster or zoom when locations become dense.
03
Flow map · talent has a direction
Two places become a geographic story when an edge explains movement.
Flow maps connect known locations and encode volume with line width. Great-circle paths respect the globe; arc and offset styles separate overlapping or reciprocal routes. Direction, not mere connection, is the sentence.
COACH’S CHALLENGEA bright animated particle can imply live movement even when the data is a historical total. Motion should describe motion; otherwise a static line is more honest and easier to read.
04
Distance cartogram · the schedule as experienced
A flight hour can move a city farther than a thousand miles.
Distance cartograms distort location so radial distance from one origin represents travel time, fare, or another cost. The familiar map becomes a before-image; the cartogram shows the geography the team actually experiences.
COACH’S CHALLENGEOnce strength rises, compass direction may survive but literal position does not. Label the cost, show reference rings, and give readers a geographic comparison when orientation matters.
Sparkline mode is the intentional stripGeographic bearing disappears; cost runs left to right.
05
Tiled map · context has a zoom level
Add streets when the reader must navigate, not merely locate.
Raster tiles turn a projected chart into a familiar pan-and-zoom map. They are useful when block, corridor, coast, or neighborhood context helps the task. The analytical marks must remain legible above the basemap.
COACH’S CHALLENGETiles bring visual noise, network requests, attribution duties, and a strong claim of locational precision. If districts alone answer the question, the street grid is overhead.
06
Geo custom · projection without a preset grammar
Keep the geographic contract while inventing the mark.
GeoCustomChart resolves projection, dimensions, theme, hit testing, accessibility, and tooltips before handing geometry to a layout function. The layout can emit geographic areas, lines, points, and SVG overlays without rebuilding the frame.
COACH’S CHALLENGECustom geometry raises the explanation burden. Preserve recognizable coordinates, make hit targets accessible, and state which parts are measured versus illustrative.
Community, school, and team court glyphs remain anchored to real San Francisco coordinates.
Atlas review · location earns its ink
Choose the map from the geographic relationship, not the backdrop.
A map should reveal adjacency, location, movement, experienced distance, navigation, or projected custom geometry. If none of those changes the answer, bench the map.
I need to…Compare regional rates
ChoroplethValues belong to areas; normalize exposure.
I need to…Compare located totals
Proportional symbolCoordinates stay fixed; area carries magnitude.
I need to…Show movement between places
Flow mapDirection and volume must both matter.
I need to…Replace miles with cost
Distance cartogramDisclose exactly how geography is distorted.
I need to…Support local navigation
Tiled mapAdd only the context the task requires.
I need to…Invent a geographic mark
Geo customKeep projection and accessibility in the frame.
I need to…Location changes nothing
Skip the mapA ranked chart will usually read faster.
I need to…The geography is uncertain
Show that uncertaintyPrecision is part of the claim.
The map is not the territory—and it is not automatically the chart, either.
THE FIFTH RULEName what location contributes before drawing the map.