How to Delight With Statistics
Etymology, the study of word origins, often interests people otherwise
uninterested in language. The reason, surely, is that etymology is tethered to
ordinary life in ways that are easy to grasp. Anyone can enjoy knowing how a
$10 bill came to be called a sawbuck (the Roman numeral "X" that appeared on
early notes reminded people of the wooden sawbuck used in carpentry), or how
the word "robot" came into English (it comes from the Czech word "robota,"
meaning "drudgery," and was part of the title of a widely popular 1920 Czech
play), or how the Indo-European root for "beech tree," "bhago-," gave us the
word "book" (Germanic tribes used beech staves to carve runes on). We like
etymologies because they tell us stories.
There would be no telling of stories at all, of course,
without grammar. But people uninterested in language issues are content to
remain uninterested in grammar. Grammar, the genetic blueprint of meaning,
operates at a level of abstraction. Nouns and verbs and other parts of speech
are considered not as familiar individuals but as members of different species.
Their interactions are considered as elements of an ecosystem. Grammar is hard
to visualize, and it is harder to enjoy.
Or at
least it was, until a man named Edward R. Tufte began to publish his work about
the display of information in the early 1980s. Tufte has produced three books
that make it possible to see the dynamics of linguistic grammar in a
brilliantly synesthetic way--books that succeed in this task by not having
grammar as their ostensible subject at all.
Edward Tufte is a professor at Yale who teaches
courses in statistics and information design. In 1983 he produced an elegant
book with the unprepossessing title The Visual Display of Quantitative
Information , which both explained and demonstrated certain rules for
presenting numerical data in a graphically arresting manner. This tour de
force--written, designed, and published by Tufte himself--was immediately
recognized as a classic by data wonks and makers of fine books alike. It has
never been out of print.
In his
analysis of such improbably compelling genres as railroad schedules and balance
sheets, chemical symbols and weather summaries, Tufte reprinted numerous
graphic displays that epitomized the statistical draughtsman's conceptual art.
In the French engineer Charles Joseph Minard's 1861 encapsulation of Napoleon's
Russian campaign, for example, a compact space revealed the diminishing size of
the army, its day-to-day geographical location, the direction of its route, the
passage of time, and the gradual drop in the temperature. It is a map, Tufte
noted, that illustrates "how multivariate complexity can be subtly integrated
into graphical architecture, integrated so gently and unobtrusively that
viewers are hardly aware that they are looking into a world of four or five
dimensions."
Tufte did not explicitly spell out his ultimate intentions
in that first volume of his trilogy, but it has turned out that the whole
series has been produced according to a precise schema--as he now indicates in
the introduction to Visual Explanations , which was just published by his
company, . The Visual Display of Quantitative Information had been
devoted to pictures of numbers, he explains--"how to depict data and enforce
statistical honesty" whether the subject is traffic deaths or the distribution
of galaxies. The second book in the series, Envisioning Information
(1990), was about pictures of nouns--that is, about representational rather
than numerical reality: the depiction of cartographic information, diagrams,
and signage. (What's the best way to show sunspot activity, for example, or the
working of a subway system?) The third book, Visual Explanations , is
about pictures of verbs--that is, about displays that illustrate dynamic
processes and can therefore function as explanatory narratives.
These explanatory narratives, these pictures of
verbs, can offer remarkable insight when properly conceived. Tufte's inclusion
of John Snow's famous map of the 1854 cholera epidemic in London is a case in
point: Snow's street-by-street tracking of cholera deaths pointed unmistakably
to the culprit--the water coming out of the Broad Street pump. The pump handle
was removed at once, and the epidemic ceased.
In
contrast, these verb pictures can also smother insight when ill-conceived--as
were the charts prepared by the manufacturer Morton Thiokol to illustrate the
behavior in cold weather of the O-rings on the space shuttle Challenger. These
charts, which failed to convince NASA officials not to launch the shuttle, were
confusing--dense with invitations to second-guess, even though crucial
information that would have delayed the launch was undeniably "there"
(somewhere). The O-ring itself, Tufte makes clear, was not the only design
element whose malfunction contributed to the Challenger tragedy. After
presenting his own version of what the charts should have looked like,
Tufte writes, "There are right ways and wrong ways to show data; there are
displays that reveal truth and displays that do not."
What makes a visual display effective? Tufte lays out rules
about such things as density and emphasis, chartjunk and clutter, layering and
hierarchy, color and parallelism--all of which have synesthetic grammatical
analogs in writing. (Hierarchy, for instance, is the building of large
structures out of small ones, be they nautical charts out of soundings or
sentences out of morphemes.) Aware of the parallels between visual grammar and
written grammar, Tufte frequently makes direct comparisons that enhance one's
understanding of each. In one place he shows how the rhetorical shape of a
passage in Gibbon's Decline and Fall of the Roman Empire , with its
paired images and a ribbing of parallel verbs, finds a visual counterpoint in
works of landscape design and even dance notation. (To get the full picture, so
to speak, you'll have to look at the book yourself.) An entire chapter is
devoted to the concept of "smallest effective difference," showing how
distinctions that are subtle but clear (two light colors on a map, say) can be
far more powerful visually than any amount of heavy-handed contrast--as useful
a lesson in writing as it is in graphic design.
What one does not expect in a book of this
kind--a book that is technical even as it is beautiful--is that the author will
be not just fastidious but also an evocative and wonderfully quirky writer.
Tufte is all of these. In his discussion of one historic work--Jean Buchon's
comparison of American rivers in his 1825 Atlas Geographique --Tufte
notes how the depictions of the Mississippi and the Amazon must curl around the
page, since there's no room to show them stretched out like the other rivers.
Actually, what Tufte says is, "[T]he two rivers meander boustrophedonically
around a tight frame." That word boustrophedon describes writing that goes from
left to right on the first line, then right to left on the second, then left to
right on the third, and so on; it comes from a Greek word describing the
turning in a field of an ox and plow. Tufte, too, likes his etymologies.
