What the Hex? ~ Kaleido Analytics

I’m incredibly open to new ideas and change, but if I’m brutally honest, I must acknowledge that my inner skeptic sometimes whispers (perhaps shouts), “Change is good—you go first.”

There may be something in my Myers-Briggs Type (I’m an ENFJ) that can explain this tendency, but regardless, I recognize that I often need to research, discuss, and think about a new idea before I’m ready to embrace it. Will I decide, “That’s a knuckleheaded idea, and hell no, I won’t go!” Or will it be, “You dumbass—why didn’t you think of that?” For example, will I choose my favorite, tried-and-true visual for displaying geospatial data, the Choropleth map, or the modern and rather sexy, but not my favorite, Hex-Tile Map?

First, let me explain why the Choropleth map works so well.

The Tried-and-True Choropleth Map

A Choropleth map (the name comes from the Greek meaning “area/region” or “multitude”) is a thematic map in which geospatial areas are shaded or patterned in proportion to the measurement of the statistical variable displayed, such as population density or, in the example below, the rates of uninsured adults in the U.S.

Choropleth maps provide an easy way to visualize how a measure differs across geographic areas and the variability within a region by saturations of color to represent the low values (low saturation) to high values (high saturation).

In the following display of uninsured adults (captured by the 2016-2017 U.S. Census Bureau, American Community Survey), we can see from the dark blue color that Texas has the highest uninsured rate of about 17%, while the lightest saturation of the blue color is in Massachusetts, where we enjoy an uninsured rate of about 2.7%.

A Choropleth Map of the U.S. displaying states colored in saturations of blue representing the uninsured rates in the U.S.

The power of this display is that it allows the viewer to quickly and easily see and understand where the higher and lower rates of uninsured adults are across the country—to understand and consider the data at a glance. I also like being able to see each state in a way that is familiar to me, i.e., the actual shape of each state, how large or small it is, and its borders to other states.

The Modern Hex-Tile Map

Next, let’s consider the genesis of the Hex-Tile Map and those few instances when I can accept that it may be useful. Most often associated with game board design (remember Dungeons and Dragons?), a Hex-Tile Map, short for the six-sided or hexagon shapes closely tiled together, has the advantage of all the shapes being identical in size, eliminating any potential incorrect perception about the proportions of the information displayed on a traditional geographic map. The Hex-Tile Map helps reduce or eliminate the “Alaska Effect”—the potential distraction or misperception caused by the fact that Alaska is really, really big (2 times bigger than Texas) and not near the rest of the states in proximity.

Some will also argue that because the states in the eastern part of the U.S., especially those along the Northeast Seaboard, are typically far smaller than those in the western portion, it is harder to see and consider the values displayed in those states. The data shown above in the Choropleth map is displayed below in a Hex-Tile Map, but now since each state is the same size, those smaller New England states are more accessible to compare to all other states.

Hex-Tiled Map of the U.S. displaying states colored in saturations of blue representing the uninsured rates in the U.S.

While these reasons haven’t persuaded me to trade in my Choropleth for Hex-Tile Maps when displaying this type of rate data, I must admit that the equally sized tiles can be an effective method of displaying simple “yes/no” data and provide a fresh and modern design.

Consider the visual below, where states are colored based on whether they have or have not expanded Medicaid under the Affordable Care Act (ACA). Undoubtedly, it’s very easy to see each state’s status and consider and understand the information quickly.

Hex-Tiled Map of the U.S. colored in blue and gray where gray represents states that have expanded Medicaid and gray states have not.

Additionally, when made interactive to serve as a filtering or navigation tool in a multi-faceted display, these maps provide an excellent alternative to drop-down lists and radio button selections.

So Am I Open to New Ideas and Change?

Choropleth maps were a complete game changer when they were used by Dr. Jack Wennberg to show unexplained variations in healthcare delivery in the U.S. (check out the Dartmouth Atlas of Health Care). The map’s impact has been profound, raising our awareness about the disparities and variations of care delivery in the U.S. system and moving people to question the status quo. I found them so thoroughly captivating that I quit my job and went back to graduate school for a second time, changing the focus and trajectory of my career—talk about change!

I may be slowly coming around to Hex-Tile Maps for certain limited circumstances, and at the end of the day, I see a few simple uses for the Hex-Tile Map – and what the “Hex” – a little bit change never hurt anyone… much.