Lever

Often when you step on the bathroom scale, what you have in mind is a figure about your size or a wish - oh, say - say ten pounds minus your usual size. Close your eyes, picture a magic figure and nine times out of ten it will be wrong when you look at the display.

Now think about the weighing scale with a lever that goes up and down like a seesaw. Though little known among young people on diet now, this scale was popular some thirty years ago. In case you have difficulty recognising such scale, go to the market and see how the old guys put the fruit or vegetable on one pan and add standard masses on the other pan until the beam is as close to a horizontal line as possible. The same applies to measuring our own body weight on the lever. Step on the base, and set the weight by moving a sliding weight to and from the fulcrum. Hmm... how about 120 pounds? And then the lever arm goes up. You must have taken too many muffins and cakes. So let's slide the weight to the right by one notch, waiting for that lever arm to fall again. Tap, tap. The lever arm moves, but just a little. Fine, let's move it by five notches, tap, tap, tap. The lever arm falls but then overshoots. Try again by going left.

Yeah, that's pretty similar to what we call diagnostic accuracy and calibration in guessing the true answer when doctors see patients. We come up first with an answer with somewhat fair confidence, and struggle around as we move back and forth. You don't have to move the sliding weight too much if you aren't confident in guessing your body weight. Go slow. In other words, zero in on the true answer bit by bit. Consider its similarity with doctors' search for an answer. The less confident a doctor is, the more diagnostic tests he will request. The catch is, doctors move the "sliding weight" but can't see the "lever" in real-world cases. That means shooting one after another, but without being told how far or how close one is from the bull's-eye. Which is why doctors' level of confidence won't be that sensitive to diagnostic accuracy and case difficulty - and definitely worse than the accuracy of guessing your body weight.

Candy

As mentioned few days ago, I found Ian McEwan's Sweet Tooth a breezy and good read.  If Candy Crush is enticing, Sweet Tooth is more entertaining. Oh, surely I exaggerate. But not much.

All right, I'm exaggerating because I never play Candy Crush.

It does seem an odd thing - it strikes me that this mobile game has been downloaded some 500 million times in the past year - that I have never spent one single minute on this popular gumdrop game. To be sure, the game has its own sweet tricks to get people hooked. Much as people with weakness should never try LSD or cannabis, I find it stupid to let a greedy toddler open a box of candy. Yes, I suppose I can't resist the temptation to keep renewing my lives in the Candy Crush game. To get around the sweet trick, I decided not to touch the candy at all.

And without strong mind to resist from getting addicted to Facebook or mobile games, I have never installed Facebook at my iPhone. So far, so good. Even with my recent addiction to Words with Friends, for example, I won't be able to play unless in front of my laptop computer. So far, this strategy works. So far.

Paint-by-Number

After Ian McEwan's novel, I picked up a new book, NurtureShock.

To see how this book gets me hooked, consider the opening pages of its introduction. Po Bronson has a knack for writing stories to illustrate parenting. He talked about his nagging wish to dump the acrylic painting in his guest bedroom. What made him hate the painting was a sense of lacklustre copycat robot art that arises from a paint-by-numbers kit. He simply doesn't like how his wife's great-grandmother bought the paint-by-numbers kit and duplicated the painting.

Is it too much to think of paint-by-number kit as a kind of cautionary note for parents?

At stake is the very idea of conformist's don't-ask-me-why-and-simply-follow-the-number dictum. I sense it when my daughter happened to receive one paint-by-number watercolour and one sticker-by-number mosaics craft this month. Both gifts are set in such a way to literally fill in the blank after matching colour with the number. What we have in our heads are rules like one equals red and two equals blue, and nothing else. You just follow. The better you memorise the rules, the quicker you'll finish the work. You need to trust the pattern. You want to avoid at all costs mixing up the numbers and colours. Your product should confirm and look exactly the same as what appears on the package.

So I teamed up with my daughter to do the job. Red, yellow, and blue. One by one. We kept decorating the mosaics by fitting together small pieces of coloured stickers. The stickers looked nice, petite and sparkling. And those pieces finally made a mermaid. And at this point my daughter told me, as excited as a pirate who found a treasure box, that there were many pieces of extra stickers. I didn't know what to do with them, but my daughter stared at them like real jewels.

She said, "Oh, wow! I think it's now the time for fun. Dad, the blue sticker is just perfect for making a bubble, a bubble that our mermaid blows under the water. Now, what about this red one? Let's imagine and create our own picture."

List

It's customary, at the end of the year, to rate the top stories in the news. It's the time of the year when everyone looks back.

Time whizzes by really quick, and I didn't write too many blog entries this year. Now I count awash in shame. I didn't say it was logical, I said it happens. It's easier to invent reason not to write than come up with a topic to write - that I know.

But.

But there are good things about this year. I read as many as before, and perhaps more. Looking back, I can think of brilliant books that I'd read this year. Here are 10 great choices that I happened to pick this year.

Thinking, Fast and Slow by Daniel Kahneman

The Power of Habit: Why We Do What We Do in Life and Business by Charles Duhigg

Justice: What's the Right Thing to Do? by Michael J. Sandel

The Glamour of Grammar: A Guide to the Magic and Mystery of Practical English by Roy Peter Clark

Could Do Better!: Help Your Kid Shine At School by Phil Beadle

Making to Stick: Why Some Ideas Survive and Others Die by Chip Heath and Dan Heath

The (Honest) Truth About Dishonesty by Dan Ariely

The Book of Dads: Essays on the Joys, Perils, and Humiliations of Fatherhood by Ben George

Case Histories: a Novel by Kate Atkinson

Sweet Tooth by Ian McEwan

Wait. Not all books are new and the last one that keeps me turning the pages at the end of this year is Ian McEwan's The Child in Time.

Hands-on

"Close your eyes, daddy," my daughter exclaimed once I went home last evening. "Close your eyes."

I did so, and when I opened my eyes it was a new house. Vast terra incognita of wit. There had been a lot going on when I went to work. That's the first Monday of Jasmine's term break. My wife took a day off, and I didn't. My child simply created a dream house. You have to try to guess what it is made of. Cut and stick, draw and paste, think and pretend. The new house is all about firing up her imagination.

Shoe boxes, empty toilet paper rolls, handkerchief, and tonnes of creativity. They were good enough to make chairs, kitchen, fridge, potty, bathtub, bedroom and whatever-you-can-dream-of. Make a grid on the cardboard box, draw few circles and they are stoves, draw a square and it's an oven.

When my daughter was cleaning up the craft materials, she found a crumpled sticky tape balled into a small piece. Jasmine was shaking her head. "Sticky and yucky."

"Not really," my wife replied, "That sounds like a bulb."

Within a minute, the idea lighted up like a cartoon's bulb. Jasmine glued the "sticky and yucky" ball on the ceiling of her new house, and told everyone her house is now brightened. She flashed me a megawatt smile that could have powered the whole town for an hour.

Face

For reasons I accept but will never fully understand, all the characters in the Thomas and Friends series won't look the same to toddlers. Ask a preschooler to get aboard the train Thomas, and he will never mistaken that for Bertie or Gordon. Of course, not everyone can do that. I can't.

It seems that there are both genetic and acquired elements in our ability to recognize faces. Oliver Sacks, the author of Awakenings and The Man Who Mistook His Wife for a Hat, was born with an inability to parse the visual aspects of a face. Dr. Sacks could not even recognize his own face. On one occassion he turned to the restaurant window and began grooming his beard. In fact - and here's the greatest shock - he wasn't looking at his reflection but another gray-bearded man on the other side of the window.

At the other end of face-blindness spectrum, some guys have incredible and indelible memories of almost every face they have ever seen. I happened to meet one such expert few weeks ago at my hospital. I had my usual morning round with my teammates, going through the story and laboratory results of one new patient. He listened carefully, gazed at me, and let me examine him. Then he leaned back and seemed to take a deep breath. "Doctor, were you working in this hospital fifteen years ago?" This was followed by everyone's curious look on me. "It's my photographic memory," he confirmed, and went on to tell us he was a police. There was little chance of anyone being seen by him and forgotten. I was completely floored.

"We have met before," he answered, and reminded me that his wife had been one of my patients too, back in 1997. By late afternoon, I asked him quietly the name of his wife. The name didn't ring a bell.

She died in the same year, I was told, but the family appreciated my taking care of her. I went to the computer and run through the list of patients bearing the same name. It didn't take me long to find the record of my patient's wife.

Over the next fifteen seconds or so I kept my eyes closed, and tried to retrieve the face of his wife. I couldn't. Her face had been erased. I went on to recall details of her illness. Then I started to notice that I had professional memory of her condition in forsenic detail. I have no idea what my patient looked like after fifteen years, but I remember most of her medical problems, as detailed as the finding of purple Howell-Jolly bodies in her blood.

U-Bend

I am writing these words one day after a meeting at my daughter's school. That's a meeting with the principal and school board to discuss the future structure of the kindergarten and primary school.

There have been efforts to expand the school. As parents, many of us say we want a secondary school for our children.

Reality check: There will be financial implication in building a new school, and it might not be easy to find a school which is closing down. Now that a secondary school is not guaranteed, the number of classes will dwindle. That means having one class in the first grade instead of two. The principal said that if we don't want to turn down students after kindergarten we would have to fill more students within one class in the primary school. How many of us want our children to have a place in the same primary school? Nearly all hands go up. How many of us want a bigger class?

Few hands.

But there is not much we can do about the size of the class. Which brings us, somewhat uncomfortably, to the question of whether a bigger class size translates into worse result.

This is not the way it is. As Malcolm Gladwell put it (in his recent book David and Goliath), we are operating in a U-shaped world. That means we should not expect a straight line when we plot the academic achievement against the class size. Why should there be a U-curve relationship between the number of children in a classroom and academic performance? As is too often the case in education, quality is more important than quantity. Yup, smaller class implies fewer children to follow, more time to know the children, and fewer papers to grade. But the trade-off for a smaller and smaller class is less interactions between students. Well, it's chaos when the classroom is too crowded, but it's not a good choice when the classroom is too silent. Small class size makes teaching easier until a certain point - the point when "diminishing marginal returns" sets in. Human nature simply dictates the critical point. Here's an example. You give me two minutes to write this blog, and I will end up with mistakes and rubbish. Let me have another half hour, and I'll write better. What about giving me another week? Would you expect me to spend the whole week writing this paragraph?