Cartographic Selectivity and the “Objectivity Question”

The comments elicited by readers of the imagined maps of Manhattan island  that I discussed in my last post were so interesting because they mistook the selective criteria of mapping for their objectivity.  The personalized maps featured in the Magazine of this past Sunday’s New York Times appropriated cartographical tools to  render personal spaces in the anonymous city, recalling the way we map the neighborhoods we live in and how they change with time.  But readers of the online version blamed them for offering limited perspectives of the city.  This was especially true of those posted by former city-dwellers who didn’t recognize the city as it existed in their own minds–or maps, and felt that their own mental maps were under-represented or neglected and just, sadly, not there.  We all have subjective maps that divide social space in our minds, that don’t line up at all with judging the accuracy or objectivity of maps.  As Becky Cooper, the curator of these maps, puts it:  “I’m really, really bad at geography. But I think it helped me to see maps more as biography.”  Cooper’s collection of maps are very different from, say, Cohen and Augustyn’s volume Maps of Manhattan that Tony Hiss introduced.  And they only gesture to what Henry James called the city’s “primal topographic curse”–its street grid–or the many neighborhoods that can be mapped and were mapped in the island.

Some blame might be assigned the limited demographic range of those invited to map their memories of the city, or map their memories of particular sites in a far more diverse city:  the selective criteria that each adopts might just as well be read as an invitation (or opportunity) to map your own image of the city, and otherwise unremarkable sites that you remember in identical cartographical outlines.  These maps transfigured existing maps of the inhabited island, mapping the island as inhabited by you, mapping individual memories, objectivity be damned and cartography full speed ahead:  rather than erase the role of the cartographer, behind the veil of objectivity, the cartographer becomes you.

The practice of selective notation of what qualify as a prominent site fits an age when AAA sells Trip Tik Guides that pride themselves as  accurate routing maps for trips, consciously designed as counterparts to comprehensive road maps of a region.  Trip Tik Guides hearken to medieval route-maps, providing a very selective guide–if a comfortingly narrow guide–to a world where we may all too often suffer from information overload:  they winnow the basics from the maps, a service that the AAA folks are proud to offer for any twelve destinations from any zip code.  AAA meets ADD, in other words:  these maps can help us decide what to pay attention to, or allow us to read a map when we might be too easily distracted by its contents to navigate effectively with them, or be tempted to stray off course by the inviting name of a region or a coastline that can’t fit our itineraries, or just help us plan an itinerary for our entire weekend trip.

Objectivity or the rhetoric of objectivity are central to the market for terrestrial maps.  But that rhetoric should not conceal that all maps are not only selective, but use selective criteria to make sense of space.  The  sharpness of contrasts of their selectivity as records that orient us to space–and the mental ties their selective criteria create in space–is a measure of the usefulness of maps as tools to think about a space that seems a dauntingly undifferentiated expanse before we’ve been there to visit and make it our own.

In the medieval maps known as “mappaemundi,” or maps that represent the world, “the religious importance of towns . . . determined their location and their prominence,” as John Gillis put it, rather than their location or size.  There seems some comfort in not plotting a sense of space, and of privileging Jerusalem’s position  in how medieval T-in-O maps, and the early printed world maps that retain the Holy City as their center, for the very reason that not many places even needed to be named other than Jerusalem in a map of global space.    The divisions of space in this 1485 world map suggests less interest in comprehensively identifying places or dividing space to scale than describing the configuration of lands around the city called “hierusa” and Holy Land, even as it claims to “lay everything before our eyes,” including the origins of our oceans, including “the sources of the Red Sea and the Indian Ocean”:

 

macrobian_1483

Most of the map, including the “terra incognita” of the mythical Antipodes, is blank.  Before the increasing

population of space, terrestrial expanse was still more or less undifferentiated in 1493, when sites worthy of memory were few, and maps’ contents were not read by audiences familiar with few places or sites.

Regional identifications were few, and confined to known landmarks and major rivers, all of which are less detailed than the sons of Noah, Shem, Japheth, and Ham, who hold the planisphere by its corners, as if it were a tablecloth, or the puffed cheeks of the nine curly-headed winds who float in the intermediate frame:

 

Schedel map small

 

 

 

So we might ask what are the criteria that we use to differentiate space, as much as wonder about the accuracy with which we denote place.  The new emphasis in maps of ordering place by terrestrial coordinates of location defined a model for reading space in quantifiable or measurable terms, in which a graticule of parallels and meridians offered terms for the viewer to judge distance and scale.

The selective criteria of later maps reflected not only knowledge of toponymy, or discovery an abundance of place-names, previously unknown, but the cartographical ability to delineate meanings in space.  Successful criteria of selectivity allow maps to make space available to the viewers, and cartography provides a sort of public ‘good’ to understand public space.

Although this sort of juxtaposition would not be possible to most, precise urban surveys allow maps of provocative maps of overlays, presenting maps less as sources of information than a sort of resource to “think about” space and imagine public space, particularly advantageous to urban planners.  I had hoped to include different maps of the UC Berkeley campus, one that construed spatial relations on directions, another by mapping creeks, and the last highlighting in blue routes lanes of wheelchair accessibility.  Each differently privileges information for different readers–and offers multiple views of the very same ‘space’–one concerned with routes of access and travel, another with spatial orientation to finding the individual buildings for university classes.

 

wc accessile campus routes ucb

 

 

 

 

 

large_campus_map

 

Let’s turn to San Francisco’s space, however–more challenging to map and more recognizable, and offering examples more semantically complex.  The below maps explicitly construe relations that are hidden to observers, although with considerable spatial precision, as this visualization that performs a layover between crime, trees, and cabs in San Francisco, overlapping three data sets to  visualize a Venn diagram. This is not a simple visualization of data, but a unique topography based on selective criteria:  the concentration downtown of cabs (and hence potential witnesses or bystanders) do not lessen crime more effectively than the planting of trees; though it’s hard to see trees as an active crime-deterrent, the overlay tells us about how we construct our neighborhoods as living spaces.  Or, as the man who made the map, Shawn Allen, put it, “I’m still not sure if it’s significant, or even interesting, but here it is.

 

cabs, crimes, trees in sf.

 

 

The versatility and value of the selectivity mapping techniques depends on the readiness of the cartographer to perfect a legible iconography–as well as its ability to surprise and invite viewers to reconsider space by revisiting the socio-economic differentiation of a space that we might already daily move through.

The mapping of food access is a good case in point of how maps make space look different.  Although this map includes no toponyms or place-names, the synthesis of data into a tricolor spectrum of a data overlap creates a topography of food choices available in each neighborhood.  It poses questions of how food constitutes a neighborhood’s attraction and the constraints its inhabitants face, or consider how these choices arose.  Another map employs a color-drenched spectrum, glowing in flourescent hues that denote relative access to food markets across the city:  the spectrum dominates names of the city neighborhoods, to reveal a topography of food that underlies their divisions.

FoodMarketScore

 

One might better understand the constraints its inhabitants face by a more traditional map of retail stores–both in terms of different regions’ quality of life, as well as real public health risks.  This alternate data visualization is at a finer grain, identifying seven varieties of sites of retail food stores of different colors, with liquor and convenience stores noted by a simple dot of black.  This makes the map both more detailed and less easily readable for some, but provides a meaningful view of the city’s urban space.

 

Retail foods SF

 

 

Successfully selective criteria can help create a map that is a better public resource.  To craft these maps of neighborhoods better, we’ve even begun to push against the preference for the visual, in maps poised to break sense-based walls as well as esthetic boundaries to register an aural dimension:

 

Sound Map of Missionjpg

3 Comments

Filed under Food Maps, Mapping Manhattan, San Francisco, sound maps, Stamen design, T-in-O, UC Berkeley Campus Map

3 responses to “Cartographic Selectivity and the “Objectivity Question”

  1. good post; good colors. Love the number & kinds of food maps! Is the food-map connection new?

  2. Wow! It’s surreal to read the themes I hoped to address in the project so thoughtfully addressed and elegantly articulated. I loved reading these two posts! I’ll be having a public event at powerHouse books in Dumbo for the book based on the project on May 16th. I’m not sure if you’re anywhere near NYC, but if you’re in town, it’d be great if you could make it!

    • Becky-

      So nice to get your note! Well, thanks so much for a piece that inspired me to write a post. I’m very glad it reached you and captured some of the themes in that neat exercise in mapping.

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