[ by Charles Cameron -- visual thinking, graphical presentation, the magical number seven plus or minus two, human intelligence ]
click image to download pdf & see pp 12-13 for closer, full-size look
Got it? That’s part of a double-page spread from the University of Maryland’s START Program report for 2011:
The National Consortium for the Study of Terrorism and Responses to Terrorism—better known as START – is a university-based research center committed to the scientific study of the causes and human consequences of terrorism in the United States and around the world.
Looking through the rest of the report, I’m tempted to say a snazzier, jazzier magazine I’ve seldom seen!
I maintain that’s far nicer to look at, but no more comprehensible than, this gorgeous and justly infamous power point slide:
click image for a closer, full size look
Got that one, too? That was a slide used to help GEN McChrystal understand that war he was fighting.
Watson and Crick introduced their 1953 paper in Nature, A Structure for Deoxyribose Nucleic Acid, with these words:
We wish to suggest a structure for the salt of deoxyribose nucleic acid (D.N.A.). This structure has novel features which are of considerable biological interest.
No less witty is the opening of George A. Miller‘s only somewhat less celebrated paper three years later in The Psychological Review, The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information:
My problem is that I have been persecuted by an integer. For seven years this number has followed me around, has intruded in my most private data, and has assaulted me from the pages of our most public journals. This number assumes a variety of disguises, being sometimes a little larger and sometimes a little smaller than usual, but never changing so much as to be unrecognizable. The persistence with which this number plagues me is far more than a random accident. There is, to quote a famous senator, a design behind it, some pattern governing its appearances. Either there really is something unusual about the number or else I am suffering from delusions of persecution.
The gist of Miller’s piece (and by gist I explicitly mean the always misleading broad strokes version) is that we can usually manage to hold five to nine chunks of thought in mind at any given time, but that if we want to understand more than that, we need to “chunk” our thoughts in such a way that we think of “seven plus or minus two” items (Miller’s “magical number”) but can peer into any one of them and see it divided into lesser portions which we can also comprehend, in what I’ll call a tree > trunk > limb > branch > twig > leaf arrangement — always remembering that a tree may be part of a forest, and that sometimes ee just can’t see the forest for the trees…
Miller explains chunking succinctly thus:
It seems probable that even memorization can be studied in these terms. The process of memorizing may be simply the formation of chunks, or groups of items that go together, until there are few enough chunks so that we can recall all the items.
Neat, hunh? And he concludes, with another pleasant touch of wit:
And finally, what about the magical number seven? What about the seven wonders of the world, the seven seas, the seven deadly sins, the seven daughters of Atlas in the Pleiades, the seven ages of man, the seven levels of hell, the seven primary colors, the seven notes of the musical scale, and the seven days of the week? What about the seven-point rating scale, the seven categories for absolute judgment, the seven objects in the span of attention, and the seven digits in the span of immediate memory? For the present I propose to withhold judgment. Perhaps there is something deep and profound behind all these sevens, something just calling out for us to discover it. But I suspect that it is only a pernicious, Pythagorean coincidence.
Of course there are high-node graphics programs like Starlight Analytics (from Future Point Systems via Battelle and the Pacific Northwest National Laboratory) which allow you to sample one of a cluster of very similar nodes, or to see where the outliers are and zero in on them…
or to focus in on only those nodes connected to one particular name or place on a map:
But can you find a file you’re looking for any faster by locating it somewhere in this graphic…
than by using your usual search methods?
So okay, high level analytics like Starlight may be useful for analysts who have the costly software and time to pinpoint and track and zoom and annotate and comprehend, become alarmed or calmed, and respond appropriately.
But people reading that glossy report from the START program? People trying to brief GEN McChrystal from a powerpoint slide?
Seven. Seven plus or minus is your number.
Once more, with feeling.
The moral of this tale is that graphical presentations of ideas to explain complexities should generally feature seven plus or minus two nodes, maximum, for eye and mind to consider at any one time, with perhaps an additional three or four that the eye can glide across to, forming a second chunk — thus delivering a maximum of 13 nodes without zooming in.
for the direct communication of major drivers in a complex situation — seven nodes plus or minus two is your optimal number.
Ah — but see, I forgot to show you the rest of that first image:
You can handle grasping the import of an image two parts, surely, can’t you?
Okay then — if you can, perhaps you can help me out…