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 Data points, in themselves, are no more naturally [[effable]] than “odd things that happen to us” from which they are extruded, of course. But numbers have the quality of submitting easily to aggregation, symbolic manipulation and statistical techniques, in a way that “odd things that happen to us” do not.
-Once one has rendered as data, one can calculate a mean, median and mode. One can formulate probability calculations.
+What one has rendered as data, one can use in calculations. With these one can generate abstract mathematical properties: a mean, a median, a mode. One can calculate probabilities.
+Applying a number to an artefact is a linguistic operation, like assigning a noun. The calculations we perform with that number tell us about the mathematical properties of the number. They do not tell us anything about the artefact it signifies. This is easy to see with an average. The average height of the passengers in this train carriage tell us nothing about any of the passengers. Yet so much of the modern world measures against the average!
+We take harvest information from artefacts, convert it into data, generalised it, manipulate it mathematically, and then apply it back to the artefacts.
 In the same way that one can calculate the probability of rolling consecutive sixes (1/36) so, it seems, one can calculate the probability of rain tomorrow, a cut in stamp duty in the spring, or a thirty-point intraday drop in the NASDAQ.
-Numbers are under our control. They ''behave''. They bend to the spreadsheet’s will.
+This is an invalid move, unless the artefacts were in the first place identical. The sides of a dice are (but for their label) identical. People are not identical.
+But numbers are alluring. They are under our control. They ''behave''. They bend to the spreadsheet’s will. The spreadsheet’s will is our will.
 Except, as [[David Viniar]]’s immortal words remind us, the events these numbers represent — the territory for which they are a map — are wont to have other ideas.
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 {{quote|{{viniarquote}}<ref>explaining why the [[vampire squid]]’s flagship hedge funds lost over a quarter of their value in a week, in 2008.</ref>}}
-But rolling dice are not like the stock market.
+Rolling dice are not like the stock market.
+====The map and the territory====
+Mr Viniar’s model, he hoped, would tell him something about the market’s behaviour. The model is the ''map'', the market is the ''territory''. We judge the success of a model by how close its prediction is to our subsequent [[lived experience]]. There is a natural dissonance: models are drawn from past experience, and that is singular, static and unalterable. It is dead.  Our future experience is, as far as we know, none of these things.
+You would not expect a “twenty-five sigma” day once in several lifetimes of the universe. Goldman’s model was in effect saying, this kind of event ''will not happen''.
+This would be the equivalent of all the molecules in a cup of tea spontaneously jumping to the right at the same moment. The molecules are bouncing around randomly — Brownian motion, right? — and so conceptually they could all jump left at once<ref>it may be that, conceptually, they couldn't — Brownian motion depends on collisions. For all I know, this implies that half the molecules are jumping the other way.</ref>
-Mr Viniar’s model, he hoped, would tell him something about the behaviour of the market. The model is the map, the market is the territory. We judge the success of the model by how close its prediction is to historical experience. You would not expect a “twenty-five sigma” day once in several lifetimes of the universe. The model was in effect saying, this kind of event ''will not happen''. That there were several such days in a row — in a market history measured in decades, not universe lifetimes — must mean the model was wrong.<ref>It was, for reasons we explore elsewhere.</ref>
+That there were several such days in a row — in a market history measured in decades, not universe lifetimes — must mean the model was wrong.<ref>It was, for reasons we explore elsewhere.</ref>
 Rolling dice to ''determine'' an outcome is is quite