336f5 | 10 years ago | on: Study says standardized testing is overwhelming nation’s public schools
336f5's comments
336f5 | 10 years ago | on: Study says standardized testing is overwhelming nation’s public schools
> I'm not saying there aren't any valid reasons for doing it.
> I'm just saying the there's a "meta-lesson" there that has to be corrected.
And I'm saying that your meta-lesson is not a good idea as it will tend to teach underconfidence. The real world does not always let you off with a "I don't know"; you may not know to some high degree of certainty whether a cancer treatment is a good idea, but nevertheless you must decide whether or not to do it.
336f5 | 10 years ago | on: Study says standardized testing is overwhelming nation’s public schools
Which is not what is being proposed by people arguing for teacher evaluations drawing on standardized testing (https://en.wikipedia.org/wiki/Value-added_modeling), as the very name 'value-added' implies.
336f5 | 10 years ago | on: Study says standardized testing is overwhelming nation’s public schools
(Imagine a test of 10 questions, each substantially harder; one student manages to answer correctly up to question 5 before starting to feel uncertain and refusing to answer any more, and a second gets up to question 6. How sure are you that #1 knows less than #2? Now imagine that they instead 'guessed' on the remaining 5 questions, and #1 got 3/5 right and #2 got 1/4. Now how sure are you? Haven't you learned something from this apparently 'useless' guessing?)
> But in the real world, there is no 25% credit for guessing.
You can no more refuse to guess in the real world than you can refuse to make choices, take actions, or let time pass.
336f5 | 10 years ago | on: Can You Get Smarter?
> Kafka was rapidly promoted and his duties included processing and investigating compensation claims, writing reports, and handling appeals from businessmen who thought their firms had been placed in too high a risk category, which cost them more in insurance premiums.[41] He would compile and compose the annual report on the insurance institute for the several years he worked there.
And of course, Wallace Stevens was an insurance lawyer.
336f5 | 10 years ago | on: Japan's hidden caste of untouchables
And what happens when AAs migrate out of America, or when Africans migrate into America, hmm? The debate is not that simplistic and easily resolved, and your professor did you a disservice by pretending that it is and not discussing why his anecdote is not airtight (for example, immigrant samples are almost always contaminated by serious selection effects which are hard to measure and vary by group). By the way, how sure are you that your professor was even right in the first place (https://unsafeharbour.wordpress.com/2012/01/13/burakumin-and...)?
336f5 | 10 years ago | on: How CEO Anne Wojcicki Turned 23andMe Around After Falling Out with the FDA
336f5 | 10 years ago | on: Research: testosterone changes brain structures in female-to-male transsexuals [pdf]
It's not that weird. If you look back in the HN archives, you can find one or two submissions from transsexual authors who argue, essentially, that after changing genders, they were discriminated against more, and that this proves that society/Silicon Valley/etc must be extremely sexist & discriminatory because nothing else about them changed; many of the HN commenters agreed with the claims.
336f5 | 10 years ago | on: The Lost History of Gay Adult Adoption
No, it doesn't. The article vaguely alludes to a third-hand description of the failure of a legal tactic which taken literally is nonsensical; and as far as I can tell, when those two people tried in the sensible standard manner used by everyone else (the manner in which the article is about), did succeed.
336f5 | 10 years ago | on: The Lost History of Gay Adult Adoption
336f5 | 10 years ago | on: The Scientific Basis of Cryonics
You probably lose at least that many neurons over a lifetime; consider the shrinking volume of the brain with age. And losses definitely easily exceed 1% in early Alzheimer's or dementia, but while not fun, people with early Alzheimer's clearly have not died or ceased to exist!
(And anyway, the real question about the dead cells is whether they still have the information about their synaptic weights and other functional information. Being able to revive the cell is overkill; the focus on revival is as an _a fortiori_ argument, since any revival proves that, even in the absence of future scanning advances, it must be possible.)
336f5 | 10 years ago | on: Shinichi Mochizuki and the impenetrable proof
336f5 | 10 years ago | on: Perceptual Image Compression at Flickr
An analogous situation: if someone runs a blood pressure clinical trial, whose results will you believe more - a trial which measures one person's blood pressure on and off a drug several hundred times over a year or two, or a trial which measures several hundred peoples' blood pressure at the beginning and end of the trial? Obviously the latter, because we know that there are big differences between people which must be measured if we want to make reliable predictions about the effect of the drug in the rest of the population, while additional blood pressure measurements of a person only reduces variability a little bit and helps only a little (because most of the sampling error was removed by the first pair of measurements, and further measurements leave the bulk of variance unaffected).
336f5 | 10 years ago | on: Motorists are using video cams to avoid disputed accident claims
336f5 | 10 years ago | on: The Most Important Thing: Decline in poverty, illiteracy and disease
Indeed, China's success has been a great testimony to the efficacy of centralized planning and communism...
336f5 | 10 years ago | on: In Some Cultures People with Schizophrenia Like the Voices They Hear
336f5 | 10 years ago | on: The History of the Design of Unix’s Find Command (1995)
336f5 | 10 years ago | on: Perceptual Image Compression at Flickr
Based on what criteria, exactly? 606 comparisons is more than enough to rule out large differences, especially considering that the testers were heavily primed to look for even the tiniest difference and making forced-choices about difference or no difference. Less than 1% difference suggests no real difference.
336f5 | 10 years ago | on: Volkswagen Is Ordered to Recall Nearly 500k Vehicles Over Emissions Software
336f5 | 10 years ago | on: How David Hume Helped Solve My Midlife Crisis
How truly awful. He mastered Tibetan, spent decades studying the profoundest and subtlest Buddhist philosophy with great success, wrote it all up for the Europeans back home whose understanding was de minimis, and from reading old books I could well credit that his work was superior to anything published until 1900 (or perhaps later) - implying the Catholic Church singlehandedly set back understanding by over 179 years, for reasons that strike one as either incompetent or psychopathicly malicious.
And this is just the summary by Gopnik, who is trying to paint the Catholic Church in as positive, tolerant, and globalizing a way as possible!
On the contrary, I addressed it entirely. mschuster91 seems to be under the impression that the teacher evaluation schemes boil down to nothing but the simplest possible before-after comparison of grades of students, ignoring all issues of demographics, differing student quality, differing school circumstances, etc. Such a scheme is indeed absurd, as his counterexample proves, but it is not what has been proposed by pretty much everyone! The actual proposals are well aware of what he thinks is the fatal problem, and go to often elaborate lengths to model and adjust for these sorts of heterogeneities in order to quantify the value-added of a particular teacher. The problem is recognized, included, and mostly dealt with. Whether the solution works entirely or is worthwhile is unclear, but he's arguing against a strawman.
> One estimate has ~12% of NYC public school teachers being punished by the flawed VAM in use there:
So I've looked at http://mathbabe.org/2015/04/02/the-arbitrary-punishment-of-n... and I have zero idea what she is trying to show. She assumes independence and treats it as a coin flip. Ummm.... what? With that sort of logic, you could show no one could expect to score a 1600 on the SAT. When criticized she links to a real analysis†, which shows considerable non-independence which means her numbers are wrong and will overstate how many will be denied tenure based on the VAMs. By the way, why are you phrasing it as 'punished'? That sounds like you're assuming your conclusion. If VAM doesn't affect hiring decisions, there's no point to bothering with it in the first place is there, but if it does affect hiring decisions, that means teachers are being 'punished'...?
† not that I think too much of it either, since it relies mostly on an argument from incredulity and pointing angrily at some scatterplots, and tries to ignore the r=.35 correlation of ratings from two subjects; to put an r=.35 in perspective, the correlation between years of education and intelligence is only ~r=.55! Even the best IQ tests won't correlate with Gf more than r=.7 or so. r=.35 is pretty good for a single pair. I don't know why he thinks a .24 is 'minuscule' when that means you're predicting half of variance... (I wonder if this is a graphing problem? He doesn't seem to jitter the datapoints, which for a large amount of discrete data will hide a lot of the density; a plot of r=.35 of n=6k should look much more striking, like this: http://imgur.com/KcwmJJH ) For implications, look at the first graph and think about classification rates. Look at the datapoints at 100 along one axis, then look across to see how many correspond to <10 on the other; hardly any do, and the 100s are almost all mapped onto 80+ on the other axis. Or look at the 0s. In terms of identifying the bottom decile, it's doing a good job.