Sunday, July 17, 2011

Some Now Or More Later In Moth Reproduction

The abstract from a (gated) paper by Nokelainen et al:
[Wood tiger moth males] have two distinct colour morphs: white and yellow. The efficacy of the warning signal of these morphs was tested by offering them to blue tits in the laboratory. Birds hesitated significantly longer to attack yellow than white males. In a field experiment, the survival of the yellow males was also higher than white males. However, mating experiments in the laboratory revealed that yellow males had lower mating success than white males. Our results offer an explanation for the maintenance of polymorphism via trade-off between survival selection and mating success.
Yellow moths are less likely to be attacked because their conspicuous color acts to fend off predators. On the other hand, the authors cannot suggest a clear reason for why white male moths have greater mating success. Whatever the mechanism is, this is a clear example of some now vs more later in evolution.

Saturday, July 16, 2011

Bill Simmons' Rating Nihilism

Earlier he claimed, on scarce evidence, that "Rotten Tomatoes scares me as a metric," because "people are idiots," and that "their 'top critics' rating is much more useful."[1]

Now he explains that:
I believe Michael Jordan is the greatest basketball player ever, and I can prove it. I believe The Breaks of the Game is the greatest sports book ever, but I can't prove it. Books can't be measured that way — they hit everyone differently, so when we're evaluating them, we can only say, "You can't mention the greatest books (or albums, paintings, TV shows, movies or whatever) without mentioning that one." That's as far as you can go.
I don't get it. He thinks you can sort of rate movies (if you trust only the experts), but you can never rate books except for saying which ones are "among the best"? This is inconsistent.

He's right that there is a key difference between sports and film/writing, although it is not, as he claims, that the latter "hit[s] everyone differently." The difference is that in sports there is a known goal--for the team to win. That means that, at least theoretically, it is possible to tease out which player stats tend to correlate with winning, and then use those stats to evaluate players.

But notice the causality here. We can't evaluate individual players well until we know which stats are generally good indicators that a player will help eir team win. Intuition does not necessarily serve well here, an insight upon which books have been written and careers have been made.

In film/writing there is no such clear objective, and thus the ratings by individuals who have seen/read them must be subjective. So instead of evaluating statistics based on how they correlate with the objective of winning, we must instead evaluate rating systems based on inter-rater reliability. The goal is that if you added more independent ratings by unbiased raters, there should be as small of a deviation as possible between the new and old ratings.

The obvious suggestion is that, if we want better opinions, we need more of them to average out more of our random biases, like how hungry we were when we first saw the movie.

Again, the input must be subjective. But once we've decided upon the best rating system, its output is objectively our best estimate of that film/book's quality. Just as in sports, personal intuition is not the best estimate of quality, and to believe otherwise is simply hubris.

Perhaps it should not surprise us that a key opinion maker is arguing that we should only trust key opinion makers, instead of wide-scale opinion aggregators. But the rest of us don't have to buy it.


[1]: Rotten Tomatoes ratings have many problems, like the fact that they threshold scores into "good" and "bad" and count the percentage of each instead of employing a continuous scale. But that is a straw man for the claim that open, aggregated movie ratings are bad.

Sunday, July 3, 2011

Venkatesh Rao On Protection vs Freedom

Rao explores an application of this trade-off,
[The] industrial age of mass-scale production required paycheck workers. People who had to be trained in industrial-style schooling.... [The] unpublicized purpose was to create a class of people that was far more disciplined and risk-averse than natural for the human species. In other words, a domesticated, comfort-loving species. This was achieved through, quite literally, conditioning. Bells rang for waking up and meal-times. Food appeared magically. Retirement was taken care of. Everything happened like clockwork. 
The first few generations resisted being drafted into the industrial workforce mightily. Not despite their intimate familiarity with risks ranging from bad harvests to disease, hunger and death through poverty, but because of it. Because they understood that with those risks came freedom. After that, the next generations were born and raised in captivity and never had a chance to sample the environments that might have made their wilder risk-taking instincts come out.
I get anxious when I read the word "generation", since it's so hard to define the gradients of separation. But thinking back on the older films I've watched, some of them (e.g. Modern Times) do explore this anxiety of becoming trapped by industry.

If Rao is right, does this indicate that part of the "wiseness" of earlier generations can be encapsulated as a more thorough understanding of trade-offs?