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On the importance of procrastination

“I had been preparing myself (though I did not always realize it) from the day that I was born, preparing myself, wrote Harsnet (typed Goldberg), but always aware of the dangers of beginning too soon. For there is nothing worse, he wrote, than beginning too soon. It is much worse to begin too soon, he wrote, than not to begin at all. Much worse to begin too soon than to begin too late. Much worse to begin too soon and realize one has begun too soon than to begin too late and realize one has begun too late. Much worse to begin too soon and realize one is inadequately prepared then to begin too late and realize one is over-prepared. Much worse to begin too soon and reach the end too quickly, typed Goldberg, squinting at the manuscript before him, than to begin at the right time and discover one has nothing to begin. That is why, wrote Harsnet, I have been preparing myself for that moment for a long time, that is why I have cleared the decks and prepared the ground, because unless the decks are cleared and the ground prepared there is little hope is succeeding in what one has planned to do, little hope of achieving anything of lasting value, though lasting is a relative term and so is value and whatever it is one has planned to do is certain to be altered in the process, which does not of course mean, he wrote, that one can start anywhere at any time. It is just because whatever one has planned to do is bound to be altered in the process that it is important to start at the right moment, he wrote. It is just because whatever one has planned is bound to change as one proceeds that it is fatal to start too soon or too late, though it may be no less fatal, he wrote (and Goldberg typed), to start at the right time, for then there is no excuse, no excuse whatsoever. I have done with excuses, wrote Harsnet (typed Goldberg), I have done with excuses towards myself and towards others, that is the meaning of the right time, he wrote, that I have done with excuses, that I have used up all the excuses and reached the bottom of excuses, that I have wrung the neck of excuses, that I have settled the hash of excuses. To begin at the right time, he wrote, means to be done with the excuses once and for all. Excuses, wrote Goldberg in the margin of his typescript with a felt-tip pen, an end to excuses…”

From The Big Glass by Josipovici

Winsorising

Winsorising is named after Charles Winsor (Huber, 2002), with whom Tukey had (a mean of) 1.9 meals per day over a period of 3 years (Fernholz and Morgenthaler, 2003).  Winsor, an “engineer-turned-physiologist-turned-statistician”, converted Tukey to stats (Brillinger, 2002).

A nice biographical detail about Winsor (from here):

I have heard gossip
that he was brilliant,
lazy and died young.

References

Peter J. Huber (2002).  John W. Tukey’s Contributions to Robust Statistics.  The Annals of Statistics, 30(6), 1640-1648.

Luisa Turrin Fernholz and Stephan Morgenthaler (2003).  A Conversation with John W. Tukey.   Statistical Science, 18(3), 346-356.

David R. Brillinger (2002).  John W. Tukey: his life and professional contributions. Annals of Statistics, 30, 1535-1575.

(For the FBI agent who, enquiring about a sister, asked “Who is in her network?”)

Who is in my network
What links us to be exact?
Better to ask to understand the force
that cuts through rock the water’s course,
and binding like to like
makes also opposites attract.

Who guides the earthworm underground,
and makes the stubborn ants persist?
When wind and rain erode the land
who calls the root work to resist?
And what clandestine hand inscribed
the coded message in the seed?
Who masterminds the spider’s web
and plans the strategy of the weed?

What inspiration could invent
the infrastructure of the vine.
the grass revolt against cement,
the rebellion of the dandelion?
What force undermines the walls
to make then crack
or makes the branches of the tree
when cut grow back?
Who conceals the passages between death and birth?
Who leads the revolution of the earth?

Who is in my network
What links us to be exact?
Better to ask to understand the force
that cuts through rock the water’s course,
and binding like to like
makes also opposites attract.

Investigate the daisies for invasion of the lawn,
or the ivy for trespass where it wants to grow.
Indict the sky for pouring out its rain,
contributing to the rivers overflow.
Arrest the seagull for unlawful flight,
impose a boundary to confine the sea,
demand a mountain modify its height,
dare my woman-spirit to break free.

Susan Saxe

[Spotted thanks to Jamie.]

Individual differences (continued)

“I am surprised that the author has used this data set. In my lab, when we collect data with such large individual differences, we refer to the data as ‘junk’. We then redesign our stimuli and/or experimental procedures, and run a new experiment. The junk data never appear in publications”

—An anonymous reviewer in 2005, commenting on research that sought to model individual differences in cognition.

From the intro to Navarro, D. J.; Griffiths, T. L.; Steyvers, M. & Lee, M. D. Modeling individual differences using Dirichlet processes. Journal of Mathematical Psychology, 2006, 50, 101-122

Death and furniture

Found this paper by Edwards, Ashmore, and Potter (1995) amusing as recently I tapped a table to make a point about different levels of analysis. From the intro:

“When relativists talk about the social construction of reality, truth, cognition, scientific knowledge, technical capacity, social structure, and so on, their realist opponents sooner or later start hitting the furniture, invoking the Holocaust, talking about rocks, guns, killings, human misery, tables and chairs. The force of these objections is to introduce a bottom line, a bedrock of reality that places limits on what may be treated as epistemologically constructed or deconstructible. There are two related kinds of moves: Furniture (tables, rocks, stones, etc. — the reality that cannot be denied), and Death (misery, genocide, poverty, power — the reality that should not be denied). Our aim is to show how these “but surely not this” gestures and arguments work, how they trade off each other, and how unconvincing they are, on examination, as refutations of relativism.”

And the point about levels is made:

“It is surprisingly easy and even reasonable to question the table’s given reality. It does not take long, in looking closer, at wood grain and molecule, before you are no longer looking at a “table”. Indeed, physicists might wish to point out that, at a certain level of analysis, there is nothing at all “solid” there, down at the (most basic?) levels of particles, strings and the contested organization of sub-atomic space. Its solidity is then, ineluctably, a perceptual category, a matter of what tables seem to be like to us, in the scale of human perception and bodily action. Reality takes on an intrinsically human dimension, and the most that can be claimed for it is an ‘experiential realism'”

Reference

Edwards, D., Ashmore, M., & Potter, J. (1995). Death and furniture: The rhetoric, politics and theology of bottom line arguments against relativism, History of the Human Sciences, 8, 25-49.

Maximum likelihood

From an old post to the R mailing list by Peter Dalgaard:

“the possibility of finding maximum likelihood estimates by writing up the likelihood and maximizing it is often overlooked…”

R really is magical sometimes. Suppose you want to fit a distribution, M. All you need is to maximise \(\prod_{i=1}^N P(x_i | M)\), or equivalently, \(\sum_{i=1}^N \log P(x_i | M)\). Here’s an example of fitting a Gaussian, starting by breaking a fairly good first guess…

> x = rnorm(1000, 100, 15)
> f = function(p) -2*sum(dnorm(x, p[1], p[2], log=T))
> optim(c(mean(x)-50, sd(x)+15), f)
$par
[1] 100 15

$value
[1] 8193

$counts
function gradient
69 NA

$convergence
[1] 0

$message
NULL

(Well actually -2 times the log-likelihood.) Now to have a look at your estimate:

hist(x, probability=T)
curve(dnorm(x,100,15), min(x), max(x), add=T)

Psychological assessment at NSA

The Memory Hole managed to obtain all non-classified forms used at the NSA (claims NSA). Two nice finds:

If you got here via Google because you’re applying to work for NSA, probably best not to email me about the assessment, eh? (Yes, some people have.)

Robin Cook’s resignation speech (17 Mar 2003)

(Full text over here.)

… It is not France alone that wants more time for inspections. Germany wants more time for inspections; Russia wants more time for inspections; … The reality is that Britain is being asked to embark on a war without agreement in any of the international bodies of which we are a leading partner—not NATO, not the European Union and, now, not the Security Council.

…

The threshold for war should always be high. None of us can predict the death toll of civilians from the forthcoming bombardment of Iraq, but the US warning of a bombing campaign that will “shock and awe” makes it likely that casualties will be numbered at least in the thousands…

Iraq probably has no weapons of mass destruction in the commonly understood sense of the term—namely a credible device capable of being delivered against a strategic city target. It probably still has biological toxins and battlefield chemical munitions, but it has had them since the 1980s when US companies sold Saddam anthrax agents and the then British Government approved chemical and munitions factories. Why is it now so urgent that we should take military action to disarm a military capacity that has been there for 20 years, and which we helped to create? …

… I have heard it said that Iraq has had not months but 12 years in which to complete disarmament, and that our patience is exhausted. Yet it is more than 30 years since resolution 242 called on Israel to withdraw from the occupied territories. We do not express the same impatience with the persistent refusal of Israel to comply.

… Nor is our credibility helped by the appearance that our partners in Washington are less interested in disarmament than they are in regime change in Iraq. That explains why any evidence that inspections may be showing progress is greeted in Washington not with satisfaction but with consternation: it reduces the case for war.

… On Iraq, I believe that the prevailing mood of the British people is sound. They do not doubt that Saddam is a brutal dictator, but they are not persuaded that he is a clear and present danger to Britain. They want inspections to be given a chance, and they suspect that they are being pushed too quickly into conflict by a US Administration with an agenda of its own. Above all, they are uneasy at Britain going out on a limb on a military adventure without a broader international coalition and against the hostility of many of our traditional allies.

… It has been a favourite theme of commentators that this House no longer occupies a central role in British politics. Nothing could better demonstrate that they are wrong than for this House to stop the commitment of troops in a war that has neither international agreement nor domestic support…