07.10.08
Thoughts on a Station Platform
“It ought to be plain
how little you gain
by getting excited
and vexed.
You’ll always be late
for the previous train,
and always in time
for the next.”
-Piet Hein
06.02.08
Investment strategy by Nicholas Taleb
A Times Online interview with Nicholas Taleb includes this one-paragraph bit of investment advice:
[T]he good investment strategy is to put 90% of your money in the safest possible government securities and the remaining 10% in a large number of high-risk ventures. This insulates you from bad black swans and exposes you to the possibility of good ones. Your smallest investment could go “convex” – explode – and make you rich. High-tech companies are the best. The downside risk is low if you get in at the start and the upside very high. Banks are the worst – all the risk is downside. Don’t be tempted to play the stock market – “If people knew the risks they’d never invest.”
04.23.08
The Spacing Effect in Learning
The spacing effect: it’s possible to dramatically improve learning by correctly spacing practice sessions. The idea is to rehearse (restudy) when the likelihood of recall drops to certain point. Repeating this flattens the “forgetting curve” (likelihood of successfull recall over time).
Long-term memory, the Bjorks said, can be characterized by two components, which they named retrieval strength and storage strength. Retrieval strength measures how likely you are to recall something right now, how close it is to the surface of your mind. Storage strength measures how deeply the memory is rooted. Some memories may have high storage strength but low retrieval strength. Take an old address or phone number. Try to think of it; you may feel that it’s gone. But a single reminder could be enough to restore it for months or years. Conversely, some memories have high retrieval strength but low storage strength. Perhaps you’ve recently been told the names of the children of a new acquaintance. At this moment they may be easily accessible, but they are likely to be utterly forgotten in a few days, and a single repetition a month from now won’t do much to strengthen them at all.
The Bjorks were not the first psychologists to make this distinction, but they and a series of collaborators used a broad range of experimental data to show how these laws of memory wreak havoc on students and teachers. One of the problems is that the amount of storage strength you gain from practice is inversely correlated with the current retrieval strength. In other words, the harder you have to work to get the right answer, the more the answer is sealed in memory. Precisely those things that seem to signal we’re learning well — easy performance on drills, fluency during a lesson, even the subjective feeling that we know something — are misleading when it comes to predicting whether we will remember it in the future. “The most motivated and innovative teachers, to the extent they take current performance as their guide, are going to do the wrong things,” Robert Bjork says. “It’s almost sinister.”
The best time to study something is at the moment you are about to forget it.
I find myself thinking of a checklist Wozniak wrote a few years ago describing how to become a genius. His advice was straightforward yet strangely terrible: You must clarify your goals, gain knowledge through spaced repetition, preserve health, work steadily, minimize stress, refuse interruption, and never resist sleep when tired.
Want to Remember Everything You’ll Ever Learn? Surrender to This Algorithm
01.19.08
Learn and Help Learn
Here is some good stuff from the closing section of the Mindsets book by Carol Dweck:
“When people change to a growth mindset, they change from a judge-and-be-judged framework to a learn-and-help-learn framework.
Every day presents you with ways to grow and to help the people you care about grow. How can you remember to look for these chances? Each morning, as you contemplate the day in front of you, try to ask yourself these questions.
- What are the opportunities for learning and growth today? For myself? For the people around me?
As you think of opportunities, form a plan, and ask:
- When, where and how will I embark on my plan?
When, where, and how make the plan concrete.
As you encounter the inevitable obstacles and setbacks, form a new plan and ask yourself the question again:
- When, where and how will I act on my new plan?
Regardless of how bad you may feel, do it!
And when you succeed, don’t forget to ask yourself:
- What do I have to do to maintain and continue the growth?
01.15.08
Cognitive dissonance
The following appears in a blog entry about the bear market (emphasis mine):
“People tend to ignore, reject or minimize any information that conflicts with their positive self-image,” their preconceived ideas and their ideological convictions, says John Nofsinger, Washington State professor of behavioral finance, in “Investment Madness.”
“The avoidance of cognitive dissonance can affect the decision-making processes in two ways. First, you can fail to make important decisions because it’s too uncomfortable to contemplate the situation,” Nofsinger says.
People hate conflicting data so much they get nervous when their preconceptions are threatened. Their brain freezes, they self-sabotage and do nothing–and their worst fears become a self-fulfilling prophecy.
The second way we handle conflicting information: “Your brain will filter out or reduce negative information and fixate on positive information,” Nofsinger says. Unfortunately, “if you ignore negative information, how are you going to realize that an adjustment in your portfolio is necessary?” Plus, you miss lots of opportunities.
11.29.07
Focus on effort, not talent
A recent article in Scientific American Mind, The Secret to Raising Smart Kids, discusses research suggesting that it is better to praise kids for their effort than to praise them for being smart. Here are some quotes:
Hint: Don’t tell your kids that they are [smart]. More than three decades of research shows that a focus on effort—not on intelligence or ability—is key to success in school and in life
teaching people to have a “growth mind-set,” which encourages a focus on effort rather than on intelligence or talent, helps make them into high achievers in school and in life.
the most persistent students do not ruminate about their own failure much at all but instead think of mistakes as problems to be solved.
How do we transmit a growth mind-set to our children? One way is by telling stories about achievements that result from hard work.
students praised for their effort did not lose confidence when faced with the harder questions, and their performance improved markedly on the easier problems that followed.
parents and teachers can help children by providing explicit instruction regarding the mind as a learning machine.
Teaching children such information is not just a ploy to get them to study. People do differ in intelligence, talent and ability. And yet research is converging on the conclusion that great accomplishment, and even what we call genius, is typically the result of years of passion and dedication and not something that flows naturally from a gift. Mozart, Edison, Curie, Darwin and Cézanne were not simply born with talent; they cultivated it through tremendous and sustained effort. Similarly, hard work and discipline contribute much more to school achievement than IQ does.
Such lessons apply to almost every human endeavor. For instance, many young athletes value talent more than hard work and have consequently become unteachable. Similarly, many people accomplish little in their jobs without constant praise and encouragement to maintain their motivation. If we foster a growth mind-set in our homes and schools, however, we will give our children the tools to succeed in their pursuits and to become responsible employees and citizens.
09.08.07
Robert Shiller on the housing boom/bust
Robert Shiller considers causes of the recent housing boom, and possible bust.
In this paper, I will consider, from a broad perspective, the possible causes of this boom, with particular attention to speculative thinking among investors. I will argue that a significant factor in this boom was a widespread perception that houses are a great investment, and the boom psychology that helped spread such thinking. In arguing this, I will make some reliance on the emerging field of behavioral economics. This field has appeared in the last two decades as a reaction against the strong prejudice in the academic profession against those who interpret price behavior as having a psychological component. The profession had come to regard all markets as efficient, and to reject those who say otherwise. Now, however, behavioral economics is increasingly recognized, and has developed a substantial accumulation of literature that we can use to give new concreteness to ideas about psychology in economics.
03.28.07
Startups
Paul Graham writes on Why to Not Not Start a Startup. Given his success with supporting projects at Y Combinator, his perspective is valuable. His essay presents a case against reasons that he has heard for not creating a startup company.
So here’s the brief recipe for getting startup ideas. Find something that’s missing in your own life, and supply that need—no matter how specific to you it seems. Steve Wozniak built himself a computer; who knew so many other people would want them? A need that’s narrow but genuine is a better starting point that one that’s broad but hypothetical. So even if the problem is simply that you don’t have a date on saturday night, if you can think of a way to fix that by writing software, you’re onto something, because a lot of other people have the same problem.
05.16.06
trac
We’re going to use trac in conjunction with subversion to manage the code for our PowerSchool deployment project. The ticket system in trac looks decent. I’m not so sure about “milestones” — my one attempt to edit a milestone ran into trouble when I entered the date value wrong and fixing that value required entering all the milestone’s fields from scratch. I either screwed up, or the interaction design of that part of trac is poor.