What if You Shade a Polygon and No One can see it?
Bigger Might be Better
Walter Kent Tierchen
State of Minnesota
What if You Shade a Polygon and No
One can see it?
Bigger Might be Be
• A >ling of regular polygons
A is organized by a large or arbitrary area
unit is more accurately distributed within that
unit by the overlay of geographic boundaries
that exclude, restrict, or conﬁne the aques>on.
• Some polygons are too small to see
• Possible solu>ons
– Hand out magnifying glasses
– Really big paper
– Delete small polygons
– Use a standard size for all small polygons
– Buﬀer small areas
• Overlapping buﬀers
• Topology errors
• From 1/10th of a square mile to over 1,000 square miles
• Average size 30 sq mi
• The maps were correct but diﬃcult to see small areas
• Choropleth issue
• Density higher in ci>es and size did not represent taxpayers impacted, typically an
• Select size and shape of tessella>on
• Tried all three regular tessella>ons, triangle, square and hexagon.
• Joe Berry stated that hexagon was the best way to represent maps.
• Tessella>on size was trial and error, needed to be small enough to represent the
smallest polygon in the layer.
• Too small would result in millions of extra cells
• Limita>ons; ci>es bounded by other ci>es (metro areas) could not be enlarged,
shape is not maintained, small areas easier to see, but s>ll small