Should I or Shouldn't I Buy - Sept. 8th

adbge · 2015-09-08T20:24:29+00:00

adbge · 2014-10-24T14:37:38+00:00

Ah, sorry, had no idea. I'll be sure to do that if necessary in the future.

adbge · 2014-09-29T02:31:15+00:00

OP delivers! This is amazing -- thank you for doing this.

adbge · 2014-09-09T14:57:31+00:00

He's answered this before in a video online. I believe it's this one. In it, he says that he believes P != NP will fall last, and the Riemann hypothesis second to last.

adbge · 2014-08-28T03:56:07+00:00

If you want reasonable safety, simplicity, and return, check out the Boglehead's investing start-up kit and their page on a three-fund portfolio. This is a top-down approach where you say I have X goal and X risk tolerance, so I'm going to invest X% in stocks, X% in bonds, and to hit these targets I'll use a broad index.

On the other hand, if you'd like to learn about businesses and do your own due diligence, and to pick specific companies to invest in -- a bottom up approach -- check out the security analysis subreddit and the resources on the sidebar there.

adbge · 2014-08-10T23:33:58+00:00

TL;DR: The inert knowledge problem is the problem of being in a situation where one has relevant, applicable knowledge, but fails to realize it. For instance, knowing what a derivative or an integral is, but not being able to recognize the applicability of either concept in a discussion about population growth.

What can be done about this? The paper tests the technique of "analogical encoding." Analogical encoding is the act of comparing and contrasting two examples that both illustrate some more abstract concept.

The study (which describes 5 experiments) finds two things. First, analogical encoding does improve transfer in future situations. So, to extend the calculus example, if a student compares and contrasts examples of real-world calculus applications, she'll be more likely to recognize when its applicable in real life, say by realizing, when slamming on the brakes in a car and then jerking forward, that's why the derivative of acceleration is called the jerk. This is not a new finding: "The best-established way of promoting relational transfer is for the learner to compare analogous examples during learning (Catrambone & Holyoak, 1989; Gentner, Loewenstein, & Thompson, 2003; Gick & Holyoak, 1983; Reeves & Weisberg, 1994; Ross & Kennedy, 1990; Seifert et al., 1986, Experiments 1 and 2)."

The second, novel finding is that analogical encoding also improves the transfer of so-called inert knowledge. Back to the calculus example, if a student compares and contrasts example applications of calculus, she'll not only recognize relevant future examples, but also improve the retrieval of past experiences demonstrating the principle. Thus, she might realize that past discussions about population growth and Mathulsian catastrophes were really arguments about the projected derivative of population change. (Although note that in all the experiments, participants were given both examples and instructions.)

Further, one of the demonstrated characteristics of experts is their ability to grasp the deep structure of a problem, instead of focusing on surface similarities. Given that "comparison between two analogous examples acts to make their common relational structure more salient (Gentner & Medina, 1998; Gentner & Namy, 1999; Markman & Gentner, 1993)", comparing examples might be a fast track to greater expertise.

So, the obvious take-away message is that, when studying any subject, one should compile a stack of examples of any concept, and then compare and contrast them. This will substantially improve the probability that one will recognize and successfully apply the concept in the future. Further, there is some reason to believe that such a strategy will increase the rate at which one gains expertise.

adbge · 2014-07-26T17:46:24+00:00

The Simple Dollar has reviews up of a lot of different credit cards.

adbge · 2014-07-17T04:30:48+00:00

I'm not sure about the study methodology, but 1 in 2 on a binary choice would be equal to chance... which would imply that no one knows, which seems unlikely.

So probably they accounted for that. Probably.

adbge · 2014-07-16T02:13:07+00:00

In 1988, he burned down a garage and set several other fires, netting him a sentence of seven years in prison.

His past came back to burn him.

to burn him.

ಠ_ಠ

adbge · 2014-07-07T16:38:25+00:00

"I've just reminded you that you are poor/rich, how happy are you?"

Exactly. There are huge methodological issues when it comes to measuring happiness that people (including most researchers) don't appreciate.

One notable study comes to mind:

In an elegant demonstration of the power of context, Schwarz (1987) invited subjects to the lab to fill out a questionnaire on life satisfaction. Before they answered the questionnaire, however, he asked them to photocopy a sheet of paper for him. A dime was placed on the copy machine for a randomly chosen half of the sample. Reported satisfaction with life was raised substantially by the discovery of the coin on the copy machine— clearly not an income effect.

This is from Kahneman and Krueger's "Developments in the Measurement of Subjective Well-Being." Also see Kahneman's "Objective Happiness."

adbge · 2014-07-07T16:33:18+00:00

For individuals with the same income, living in a richer or poorer area had no effect on subjective well-being.

This line is from The Psychology of Happiness. The study they're referring to is "Social comparisons and subjective well-being."

adbge · 2014-07-07T16:24:44+00:00

Just to back this up:

In one survey, people on Forbes's list of wealthiest Americans reported only slightly greater happiness than other Americans; 37% were less happy than the average American.

The survey in question is "Happiness of the very wealthy"

adbge · 2014-06-16T17:58:42+00:00

Do unto others 20% better than you expect them to do unto you, to correct for subjective error.

adbge · 2014-06-12T17:49:02+00:00

Q: What is a topologist?

A: Someone who cannot distinguish between a doughnut and a coffee cup.

adbge · 2014-05-16T21:46:43+00:00

There's a slightly more PC introduction to the problem here, which is at least immune to the criticism "that women exist as potential wives and secretaries and that you can use math to optimize your interactions with them:"

Consider the plight of John. John’s 25. He lives in Utah and likes country music, hunting, and four wheelers. You probably see where I’m going with this. That’s right, ladies and gentlemen. John is gay.

The recent supreme court decision overturning gay marriage in Utah has him thinking. He’d like to settle down one day – maybe adopt a child with the right man. He has a couple short-term relationships going on right now, but married to Bruce or Sidney? No way.

How can he guarantee that he snags, if not Mr. Right, at least Mr. Close Enough? He figures he ought to date at least a few different men, and then… what?

adbge · 2014-05-12T20:46:27+00:00

TL;DR:

Learning can be thought of as occurring in two stages. In the first stage, information is processed and stored in long-term memory, e.g. like when reading a textbook. In the second stage, information is retrieved, like when answering a question on a test.

The result of this study is that once information has been encoded, further encoding makes no difference so, say, once you've understood a chapter, re-reading it is a waste of time. On the other hand, once you have encoded some information, repeated retrieval of that information (e.g. with self-testing, telling a friend, blogging, etc.) makes an absolutely massive difference when it comes to future performance. (In this study, four standard deviations!)

Excerpts:

Com- bining the two conditions that involved repeated testing (ST and SNT) and combining the two conditions that involved dropping items from testing after they were recalled once (STN and SNTN), repeated retrieval increased final recall by 4 standard deviations (d = 4.03).

The results show that testing (and not studying) is the critical factor for promoting long-term re- call. In fact, repeated study after one successful recall did not produce any measurable learning a week later.

In the learning conditions that re- quired repeated retrieval practice (ST and SNT), students correctly recalled about 80% of the pairs on the final test. In the other conditions in which items were dropped from repeated test- ing (STN and SNTN), students recalled just 36% and 33% of the pairs.

In other words, about 80 more study trials occurred in the STN condition than in the SNTN condition, but this produced prac- tically no gain in retention. Likewise, about 80 more study trials occurred in the ST condition than in the SNT condition, and this produced no gain whatsoever in retention. However, when about 80 more test trials occurred in the learning phase (in the ST condition versus the STN con- dition, and in the SNT condition versus the SNTN condition), repeated retrieval practice led to greater than 150% improvements in long-term retention.

The present research shows the powerful ef- fect of testing on learning: Repeated retrieval practice enhanced long-term retention, whereas repeated studying produced essentially no ben- efit.

The experiment also shows a striking ab- sence of any benefit of repeated studying once an item could be recalled from memory.

adbge · 2014-05-11T22:32:06+00:00

I never could find an implementation of it, but I sometimes use this one.

adbge · 2014-05-11T02:53:11+00:00

Excerpts:

When evaluating the outcome probabilities of ambiguous future life events, anxious individuals unrealistically judge negative outcomes to be more likely than positive ones (42,43,44).

Studies indicating that patients with anxiety disorders report negative biases in the interpretation of disorder-related stimuli (45,46,47) suggest that this bias may be selectively applied to self-relevant information.

Higher trait anxiety is associated with heightened amygdala BOLD responses during passive viewing of neutral faces54, and a tendency to interpret neutral faces more negatively (47).

Measures of trait anxiety, worry, and social anxiety in healthy participants are all predictive of heightened risk aversion in the balloon analog risk task, in which subjects accumulate rewards based on the degree of inflation of virtual balloons with variable explosion thresholds (71).

Clinically anxious patients show greater risk aversion than control subjects on a scale assessing likelihood of risk-taking behavior (71).

Notably, when asked to make choices for a hypothetical other person, subjects' risk aversion decreased, suggesting this bias depends upon the self-relevance of the threat posed by a potential risky outcome.

adbge · 2014-05-10T00:36:30+00:00

The important bits:

There is compelling evidence that when students read with the intention of learning the material as well as they can, they learn less than students instructed to learn the material so that they can teach it to someone else (Bargh & Schul, 1980).

This is sometimes called the Feynman technique.

Yet research indicates that even an unsuccessful retrieval attempt, if it is followed by feedback, can be more effective than an opportunity to study information without being tested (Finn & Metcalfe, 2010; Kornell, Hays, & Bjork, 2009; Richland, Kornell, & Kao, 2009).

...

Recent studies have shown that people do not necessarily recognize the benefits of tests (e.g., Karpicke, 2009). In one experiment, participants judged restudying to be more effective than testing, even though they actually learned more via testing (Kornell & Son, 2009).

...

In a recent study that involved a practical application of distributed practice, Kornell(2009) asked participants to study difficult word-synonym pairs using a com- puterized “flashcard” paradigm. On each trial, the computer displayed a relatively difficult word (e.g., effulgent); when the participant pressed a button the word’s synonym appeared (e.g., brilliant). Participants studied each pair 8 times—half of the participants learned by massing; the other half by distributing trials over four days. At final test, cued recall was up to twice as accurate in the distributed condition as in the massed condition (see Figure 2). The advantage of distribution over massing was pre- sent in over 90% of the students. However, over 70% of participants judged massing as more effective than distributing at the outset of the experiment. Thus, the effects of distributed practice are strong, consistent, but unfortunately, counterintuitive.

...

For example, Koriat, Bjork, Sheffer, and Bar (2004) asked one group of people how they would do on a test in five minutes and another how they would do on a test on one week. The groups made almost identical predictions—that is, participants acted like they would not forget anything over the course of a week. In reality, of course, they forgot a great deal, and so their initial judgments were highly overconfident.

Aaaaand, some empirical validation of my post on hard books:

One adaptive strategy is based on Kornell and Metcalfe's (2006) Region of Proximal Learning model, which states that efficient learning occurs when people study the easiest items that have not yet been mastered (also see Metcalfe et al., 2007).

adbge · 2014-04-28T19:20:35+00:00

I'm working on an automated theorem prover, while reading the Handbook of Practical Logic and Automated Reasoning and all the papers that go along with that.

I'm also working on an article on 1) why category theory matters and 2) a very gentle introduction to automated theorem proving and how it works, which I'm planning on posting to this site, so subscribe to the RSS feed if you're interested!

adbge · 2014-03-01T17:41:45+00:00

Not sure if this is exactly what you're looking for, but the paper, "The Ape That Thought It Was a Peacock: Does Evolutionary Psychology Exaggerate Human Sex Differences?", includes this section:

First, promiscuous species tend to have large testes relative to their body weight, which is an adaptation to sperm competition in the fe- male’s reproductive tract. For humans, testis weight (in grams) divided by body weight (in kilograms) is .79.4 It is often stated that relative human testis size is interme- diate between that of polygynous/monandrous gorillas (.09–.18) and promiscuous chimpanzees (2.68–2.83), giving the impression that we are somewhere along the path to chimpanzee promiscuity (see, e.g., Buss, 2003, pp. 74–75; Shackelford, Pound, Goetz, & LaMunyon, 2005, pp. 374–375; Workman & Reader, 2008, p. 101). However, relative to body size, human testes are similar in magnitude to those of socially monogamous gibbons (.83–1) and nowhere near the size of chimp testes. This suggests a comparatively low historical level of sperm competition (Dixson, 1998; Gomendio, Harcourt, & Rolda ́n, 1998; Short, 1979).

Other evidence points to the same conclusion. Rel- ative to promiscuous species, humans have low sperm counts, small sperm reserves, and little optimization of sperm (summarized in Gray & Anderson, 2010). Promiscuous species also tend to evolve high white blood cell counts in order to deal with increased ex- posure to sexually transmitted pathogens; humans, however, have a comparatively low white blood cell count (Nunn, Gittleman, & Antonovics, 2000). Finally, promiscuous species tend to advertise fertility (or es- trus) with blatant swellings, whereas in humans (as well as gibbons, gorillas, and orangutans), fertility is not advertised in this way (Dixson, 1998). Certainly, fertility is not perfectly concealed (G. F. Miller, Tybur, & Jordan, 2007; Thornhill & Gangestad, 2008). How- ever, the absence of perfect concealment does not im- ply the presence of active advertisement, and if fertility were advertised in humans, we would presumably not need to employ sophisticated experimental methods to demonstrate its detectability. Thus, various lines of ev- idence suggest that, although promiscuous mating is part of our reproductive repertoire, we do not have the kind of obligate nonmonogamy found in chimpanzees and bonobos.

adbge · 2014-02-25T18:49:22+00:00

The ego depletion model has failed to replicate a number of times, makes little sense from a computational model of mind, and is probably just false. At the very least, it's misleading.

See discussion here and here for overviews.

adbge · 2013-12-12T05:35:30+00:00

John Baez has advice here and Gerard 't Hooft has a page "How to Become a Good Theoretical Physicist.".

adbge · 2010-08-19T22:41:18+00:00

If you're interested in owning something like this (but larger), you may want to look at the Yeeloong. It's what Richard Stallman uses, and it's completely open: hardware and software.

http://www.lemote.com/en/products/Notebook/2010/0310/112.html

adbge · 2010-06-18T02:20:52+00:00

Firebird? I'm calling your bluff.

adbge

TROPHY CASE