Saturday, October 30, 2004

The Importance(?) of Understanding the Mechanics and Logic of Perception

Law journals devote quite a bit of attention to studies of the reliability and unreliability of eyewitness identification. But could the legal process produce better assessments of eyewitness reports if trial lawyers and judges knew more about the technology, or physiology, of perception and the logic that informs such perception?
Caveat: It does not necessarily follow that human knowledge of perception is presently good enough to be used in the courtroom -- and, even if such knowledge is useful "in principle" for forensic purposes, it does not necessarily follow that lawyers, judges, and jurors have the training or intelligence to make effective use of contemporary knowledge of human perception.
Counter-caveat: It is not prudent to underestimate the intellectual prowess of jurors; and some lawyers and judges have a pleasing degree of scientific literacy.

The question I pose here is not trivial -- for it is an iteration of the question of the extent to which human beings understand their world without understanding it, viz., of the extent to which human beings are capable of drawing inferences about the world without understanding the mechanics that make it work as does. Conversely stated, the question posed here implicates the question whether knowledge of causes improves inference even if it is true that some inference is possible without (much) knowledge of causes.

Counterpoint: The hypothesis that perception (truly) is (pretty good) inference suggests that human beings -- by virtue of their heredity, physiology, etc. -- know much more than they can put in words.
But the question remains: Can explicit knowledge of causes improve inference?
The answer to this question would seem to have to be "yes": It is very hard to deny that some explicitly-formulated knowledge of nature's mechanics -- e.g., gravity -- enables human beings to make better inferences and predictions (predictions are merely a special form of inference) in some situations.
A final word of caution: Even a worm knows how to burrow into the soil. (Indeed, a worm probably knows how to do that better than you do.) But (as far as I know) worms have not produced treatises on soil mechanics.

Friday, October 29, 2004

Perception as Inference (again)

E.T. Jaynes, PROBABILITY OF THEORY: THE LOGIC OF SCIENCE Section 5.4 at 133 (2003):
Seeing is not a direct apprehension of reality, as we often like to pretend. Quite the contrary: seeing is inference from incomplete information, no different in nature from the inference that we are studying here. The information that reaches us through our eyes is grossly inadequate to determine what is "really there" before us.
N.B. The discussion here does not suggest that Jaynes was intimately familiar with recent research on the logic of perception. But he was prescient in suggesting that researchers should investigate whether Bayesian logic informs perception.

Support for the Proposition that Values Depend on (Perceptions of) Facts

Some years ago I argued that there is evidence in law, that the values embedded in law (even in legislation) are in part a function of beliefs about factual propositions, including factual inferences that rest on evidence. See P. Tillers, The Value of Evidence in Law, 39 Northern Ireland Law Quarterly 167 (1988). Perhaps the following statement by Jaynes (amusing footnote omitted) offers some support for my view:
We consider it an important aspect of "objectivity" in inference -- almost a principle of morality -- that we should not allow our opinions to be swayed by our desires; what we believe should be independent of what we want. But the converse need not be true; on introspection, we would probably agree that what we want depends very much on what we know, and we do not feel guilty of any inconsistency or irrationality on that account.
E.T. Jaynes, PROBABILITY OF THEORY: THE LOGIC OF SCIENCE Section 13.12.5 at 424 (2003).

Inference Is Better-Grounded than Choice; and Analysis of Evidence Is More Secure than Economic Analysis -- Is It So?

E.T. Haynes, PROBABILITY OF THEORY: THE LOGIC OF SCIENCE Section 13.12.4 at 424 (2003):
[I]t now appears that from a fundamental standpoint loss functions are less firmly grounded than are prior probabilities. This is just the opposite of the view that propelled the Wald-inspired development of decision theory in the 1950s, when priors [prior probabilities] were regarded as vague and ill-defined, but nobody seemed to notice that loss functions are far more so. For reasons we cannot explain, loss functions appeared to workers at that time to be "real" and definite, although no principles for determining them were ever given, beyond the truism that any function with a continuous derivative appears linear if we examine a sufficiently small piece of it.

In the meantime, there have been several advances in the technique for assigning priors by logical analysis of prior information. But, to the best of our knowledge, we have as yet no formal principles at all for assigning numerical values to loss functions; not even when the criterion is purely economic, because the utility function of money remains ill-defined.

Thursday, October 28, 2004

Great Law Schools & Great Libraries

My law school does not do badly in the law school ratings game. But the law school rating services play a poor game because they generally ignore one crucial measure of the greatness of a law school: the quality of a law school's library.

We can have endless debates about whether a law school either is ought to be essentially an academic institution or a professional school, or whether the academic-professional divide is a false one. But -- regardless position we take on such issues -- all sensible law teachers and legal practitioners should agree on one point: much of law centers on TEXT. Hence, a great law school, regardless of how it defines its mission, must be a great repository of textual material (cases, treatises, journals, the lot).

If a law school is to grant text its proper role in the life of a law school, the law library must be a sanctuary, and the library ought to be an inviting and alluring sanctuary. For example, the seats should be comfortable and the physical environment should be aesthetically pleasing and warm. The library must be so arranged that its "customers" want to spend time in it.

A great law school must have a great library. Does US News & World Report know this? Does Brian Leiter know this?

Apparently not.

N.B. My law school fares worse -- not better -- if "library quality" is a measure of the quality of a law school. So this post does not serve a narrowly-conceived personal interest.

Wednesday, October 27, 2004

A Stellar Conjunction -- or a (non)Lunatic One

Will the Red Sox win the World Series just at the moment that the moon goes blank? If so, are the Red Sox responsible? Or is the moon responsible? Which way does the chain of causation run? Is non-Luna pulling the Red Sox or are the Red Sox eclipsing the moon? I need a Latin phrase here. ("Post hoc, propter hoc"?)