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## [2620] Do not erect barriers to learning science and math

I am partial to an education system which has the English language as its medium of instruction. That is because I am most comfortable where English is the primary and the common language. While the Malay language is my mother tongue, I mostly use English to run both my private and professional life.

For a person with my background, it is reasonable for a stranger to expect me to be supportive of the policy (PPSMI) to teach science and mathematics in English. While I do sympathize with the policy, I oppose it.

I do not think anyone can doubt the importance of learning science and math. From the liberal education perspective, there are not too many other subjects that can liberate the mind the way science and math do. In terms of practicality, it offers a wide range of rewarding career choices.

To be good at both, one has to comprehend various scientific and mathematical concepts. The foundational lessons especially are crucial in allowing students to understand other more complex ideas. In both subjects, each concept is built upon an earlier concept. Failure to comprehend basic lessons will cause the student to struggle later. In a system where a student largely progresses based on his or her age, this can bring about a devastating snowball effect.

Learning those lessons can be harder than it is when both subjects are taught in a language that students struggle to master in the first place. That presents a two-layer barrier to mastering those basic scientific and mathematical concepts.

The language barrier adds to the frustration which can kill schoolchildren’s interest in science and math before the interest has a chance to bloom.

For many children from middle and upper-class families, English comprehension skills are not likely to be a problem. That is not true for the rest.

Consider a proxy to the mastery of the English language. Typically, families with higher incomes can be expected to have children who are better at English than those belonging to lower-income families. Here are the numbers. Based on the 10th Malaysia Plan, nearly 53% of households earned a monthly income of less than RM3,000 in 2009; about 66% earned less than RM4,000 a month; close to 76% earned less than RM5,000 a month.

The figures have probably improved since 2009. After all, 2009 was a recession year and we have recovered from that recession. Nevertheless, it is likely that a significant number of households still do not earn too much. This is a structural economic issue and such issues do not just change significantly in three years.

Notwithstanding the technical concerns about the evolution of household income over the past three years, that possibly means that more than half the children in Malaysia may have trouble with English. If PPSMI is to be continued in its blanket fashion as it was enforced earlier, that may lead to the making of a lost generation in terms of science and math education. As for the level of English, I am unsure if ­science and math classes are the place to learn English grammar, vocabulary and comprehension skills.

While I oppose PPSMI, that does not mean I think English is unimportant. I live in corporate Malaysia and in corporate Malaysia, English is the national language and not Malay. I know English is important. The inability to speak and write in English will come at a very great cost for fresh graduates and labor market veterans alike. I do believe that the teaching of English should be emphasized in all schools and at the early stages. The barrier to learning English should be reduced.

What PPSMI does to many students instead is that one, it does not reduce barriers in learning English — one does not learn grammar, vocabulary and comprehension skills in science and math classes — and two, it erects barriers to learning science and math for underprivileged children.

The point is that the teaching of English should not come at the expense of learning science and math.

At the very least, do not force students with a weak grasp of English to study science and math in English. Instead, let them improve their English in and outside of classes and let them learn science and math in the medium they understand best.

For students who already have a good command of English, let them study science, math and perhaps other subjects as well in English.

First published in The Sun on October 29 2012.

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## [2619] Why are critical values always at 1%, 5% and 10%?

I was running some regressions at work just now and I realized my overdependence on computers had made me forgotten how to calculate certain statistics manually. Modern regression softwares automatically calculate various statistics less than a second and I hardly think of what happens in that virtual blackbox.

But just now, I was following up on a technical economic debate which revolved around some statistics where the report reported its t-stats but not its probability. I was curious about its probability and so, I had to translate the t-stats into probability manually by reading the t-stats distribution table. I struggled at first. I found myself embarrassed at my inability to read the table after 6 years worth of education in economics, and another 3 or 4 years in econometrics. But I managed. I guess, it is like riding a bicycle. Once you learned it, you know it. It may take some stimulus to remember if you have not been riding, but you can really do it.

One thought came to my mind after I was done with that.

I know there is a criticism about whether the critical values—the 10%, the 5%, etc—means anything. Indeed, the critical values are rules arbitarily made up out of convenience. It is highly possible that if the calculated value breaks a particular critical value, a hypothesis can still be true despite rejection. It is all a matter of probability and probability does not work so discretely as the typical critical value rejection rule suggests. If there is a 99% possibility of a hypothesis is untrue, that 1% can still pan out to be true however unlikely. (Let us not get into the Error I and II debate)

Too many people like yes and no answer. The rejection-rule gives them that, rightly or wrongly.

But I am thinking, why, throughout the economics and econometrics world, are the critical values always the same numbers? It either 1%, 5% or 10% (I have seen 25% but… ehem). Why not 4.7%, or 7.1%?

I think I found an answer to that after looking at the t-stats table for the first time in at least 2 years.

Powerful and cheap computers were only available in the last decade of the 20th century. Because of this, many students in the olden days relied on tables for their rejection rules. Tables being tables on pieces of papers, space was at a premium. So, publishers of tables could only print sexy numbers and obviously not too many numbers over the natural number space, never mind real numbers. Either you use the tables, or calculate the critical values yourself, which is a pain.

So, that convention sticks after awhile. From early econometricians to students of econometrics, the same tables get used over and over again. It becomes a tradition.

Maybe?

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## [2495] Thought so highly that they kept 161,600,000 of it!

Fun-quotation-that-has-something-to-do-with-Australia:

…he had confessed to repeated intercourse with sheep on a recent visit to the family farm; perhaps that was how he had contracted the mysterious microbe.

This incident sounds bizarrely one-of-a-kind and of no possible broader significance. In fact, it illustrates an enormous subject of great importance: human diseases of animal origin. Very few of us love sheep in the carnal sense that this patient did. But most of us platonically love our pet animals such as our dogs and cats. As a society, we certainly appear to have an inordinate fondness for sheep and other livestock, to judge from the vast numbers of them that we keep. For example, at the time of a recent census, Australia’s 17,085,400 people thought so highly of sheep that they kept 161,600,000 of them.

Some of us adults, and even more of our children, pick up infectious diseases from our pets. Usually they remain no more than a nuisance, but a few have evolved into something far more serious… [Guns, Gems, and Steel. Chapter 11: Lethal Gift of Livestock. Page 196. Jared Diamond. 1999]

Happy Australia Day!

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## [2477] Diamond, consumer choice theory, marginal revolution, Marxian economics and the paradox of value

From those precursors of food production already practiced by hunter-gatherers, it developed stepwise. Not all the necessary techniques were developed within a short time, and not all the wild plants and animals that were eventually domesticated in a given area were domesticated simultaneously. Even in the cases of most rapid independent development of food production from a hunting-gathering lifestyle, it took thousands of years to shift from complete dependence on wild foods to a diet with very few wild foods. In early stages of food production, people simultaneously collected wild foods and raised cultivated ones, and diverse types of collecting activities diminished in importance at different times as reliance on crops increased.

The underlying reason why this transition was piecemeal is that food production systems evolved as a result of the accumulation of many separate decisions about allocation time and effort. Foraging humans, like foraging animals, have only finite time and energy, which they can spend in various ways. We can picture an incipient farmer waking up and asking: Shall I spend today hoeing my garden (predictably yielding a lot of vegetables several months from now), gathering shellfish (predictably yielding a little meat today)? or hunting deer (yielding possibly a lot of meat today, but more likely nothing)? Human and animal foragers are constantly prioritizing and making effort-allocation decisions, even if only unconsciously. The concentrate first on favorite foods, or ones that yield the highest payoff. If these are unavailable, they shift to less and less preferred foods. [Guns, Germs, and Steel. Chapter 6: To Farm or Not to Farm. Page 107. Jared Diamond. 1999]

A lot of words.

Luckily, any economics student who has his or her bases covered will understand this as $\frac{dy}{dx} = \frac{P_x}{P_y}$ in one way or the other. Simple! We can thank the marginal revolution that began in the late 19th century for that. Marginal revolution also solved the paradox of value. Indeed, marginalism is the foundation of modern microeconomics, regardless of your cup of tea.

And oh, did you know that the marginal revolution also made Marxian economics in its original interpretation completely obsolete?

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## [2437] Thanks Steve

I am not an Apple fanboy. I was anti-Apple even.

I remember the first Apple computer I used long ago. Wikipedia tells me that it was Macintosh Classic. Its screen had only two colors: green and black. I was happy of playing Karate-Ka on it, and other games that for the life of me, I cannot remember. It was my first vivid recollection of a computer. This was the time when large diskettes were used, not a flash drive, not even a CD.

My next encounter with Apple would come 8 or 9 years later when the University of Michigan had iMacs littering its computer labs. I spotted the largest collection of iMacs in Angell Hall’s Fishbowl. I had thought Apple was dead, but no. I was wrong.

These Macs were not these modern days slick-looking Macs. It was an odd one piece machine with the CPU and the monitor wedded together. The G3, Wikipedia says. The weirdest of all was the one-button mouse. Who would use that?

I was decidedly anti-Apple then.

But Apple progressed tremendously after the odd-looking bright-colored Macs. Its notebooks were becoming extremely slick and I remember spotting a 23” Powerbook, probably the first of its kind, in an Apple Store in Novi, Michigan, somewhere outside of Ann Arbor. Despite being impressed, I remember blogging my somewhat negative sentiment against Apple.

From there on, it was all up for Apple.

First, it was the iPod.

I had always wanted an mp3 player as an undergraduate but I decided against buying an iPod back in 2004. I bought a Creative Zen instead, all because I believed the iPod was overpriced, and all hype. Five years later, I am the owner of a fifth-generation iPod Nano. I did not buy it. I got it as a gift.

And I love it.

I remember bragging about having a Nano to my ex-girlfriend through Skype. She was unimpressed, showing to me that she had a Nano too. Purple. Mine was blue. There she was, a cute French girl smiling with her purple iPod.

There are of course the revolutionary iPhone and the even more revolutionary iPad. To say these gadgets were revolutionary on its own rights is an understatement. Apple not only revolutionized consumer goods. It revolutionized the global culture.

That was because of one human legend, Steve Jobs. At least, as far as I am concerned.

So, when he died today, the world has just lost one of its biggest culture icons. We are living in an exciting time, partly thanks to Steve Jobs. I do not think anybody can deny that.

You do not have to be a tech-writer to know that. You do not have to be part of the tech or creative industry to know that. You just need to live to know that.

Apple wrote on its website, it “has lost a visionary and creative genius, and the world has lost an amazing human being.” Aye to that.