What I’ve learned teaching offline and online

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The last time I wrote a piece on Medium was on July 30, 2020.

It was the longest hiatus in blogging I’ve ever been in.

2020 was a whirl down the rabbit hole.

Here’s why…

From March to June 2020, I taught online classes during the first outbreak of coronavirus.

In July, everything seemed to return to normalcy. I returned to my workplace in Taiping, Malaysia and resumed teaching real human beings for another 4 months.

For the record, students normally sit for a October/November or May/June paper test mailed straight from Cambridge, UK. …


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The impossible feat of forecasting the long-term weather has been coined by a meteorologist, Edward Lorenz, as the “butterfly effect”. Hypothetically, the flap of a monarch butterfly in Brazil can ultimately result in a disastrous tornado in Texas, US.

Butterfly effect

When a butterfly flaps its wings, it creates small wind that disrupts the heat flow. The butterfly’s imperceptible perturbation can instigate chain effects in the local wind pattern, and trigger non-linear feedback interactions in troposphere and stratosphere.

Water vapour and gas particles collide into each other to form cumulonimbus clouds. As clouds rub against each other, the atmospheric conditions are now…


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An accidental observation of a meticulous meteorologist, Edward Lorenz, has catalysed and spawned the birth of chaos theory.

The chain effects of 0.0001

In 1961, Lorenz typed in some data into a computer program that could simulate weather patterns using 12 variables, including temperature and wind speed.

To save time, he copied and pasted computer printout of weather data, then started the simulation halfway of its original course.

He left for coffee while the computer program continued to run.

One hour later, the computer program had output two month’s worth of simulated weather data. Much to Lorenz’s chagrin, the weather predictions bore no resemblance to…


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Let’s say the average height of men is 67.7 inches (172cm). If a man is 72 inches (183cm) tall, how tall will his full-grown son be?

Your first instinct might be: “Oh, that’s easy. The son will be as tall as his father.”

Although 72 inches (183cm) is a possible guesstimate for the son’s height, it is not very probable from a statistical point of view.

Correlation, regression, and standard deviation

Instead, we should compile datasets of the average height of sons whose fathers were 72 inches (183cm) tall.

We will then repeat the step above for fathers of heights 58 inches (147cm), 59 inches…


Photo by Mark Metry. Cover art by De Lin Show

Mark Metry is the podcast host of Humans 2.0 producing more than 200 episodes by now. It is one of the Global Top 100 podcasts among Gary Vee, Tim Ferriss, and National Public Radio. In this episode, Mark will share his experience interviewing Mark Manson, Dave Asprey, and Dr. Nicole LePera.

If you haven’t listened to Humans 2.0 already, please check it out on iTunes, Spotify, Google, or your favorite podcasting app.

Mark has been featured on Amazon Prime’s TV documentary series “The Social Movement” about reinventing education. He is a Forbes and TEDx keynote speaker. …


Tips for hosting online courses

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Video conferencing and virtual hangouts are the harbingers of future work. It could be the antidote for social interactions at uncertain times like this. Even if we are separated across countries and time zones, or stranded in a nationwide lockdown, we can still work, chat or meet through video calls at a safe social distance.

In this digital age, video chat apps are mushrooming and booming faster. Amidst the COVID-19 outbreak in March 2020, Zoom app was downloaded 26.9 million times worldwide.


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A majority of people I chatted online are polarized and divided on the global experimental movement of working from home. Facebook and Twitter approve of it, while Microsoft begs to differ. Most people wistfully hope to return to normalcy in the next half of the year. Several others have adapted well to the new normal and found solace in solitude.

If you have recently been on Zoom, Skype, FaceTime, Facebook Messenger Rooms, Microsoft Teams or Google Meet, all too often you would find yourself either: doing nothing or doing too many things all at once.

Chances are, you are more…


AI predicts who will drop out of college. A chatbot disguised as a 13-year-old boy passed the Turing test. AI masters chess, shogi, and Go by playing against itself. Reality is getting stranger than science fiction.

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As far back as 1954, Paul Meehl posited that a formula would outperform a human in forecasting given explicitly formalized rules and predictor variables. Today, a predictive algorithm can easily predict a student’s grade point average based on the GRE scores, faculty ratings and recommendation letters. …


Tom is a New York Times correspondent in Lebanon. He has been awarded Pulitzer Prize three times. In his book Hot, Flat, Crowded, he advocates for green revolution before 2050.

Bill is a 60-year-old retired civil servant in Nebraska. He makes forecasts voluntarily on the Good Judgment Project when he is free. He was a PhD dropout.

Can you guess who is a better forecaster?

Photo by Marc A via Unsplash

The answer is Bill. Bill Flack had a Brier score close to 0.

Brier score is similar to golf score. The lower your Brier score, the better you are at forecasting. If you get 0…


It starts with writing your goal in one sentence.

Photo by Toa Heftiba via Unsplash

“I want to have a rewarding, lucrative job with an annual income of $100,000.”

In a goal-setting study performed in Harvard MBA program, graduate students were asked to write goals and plans to actualize them. Only 3% had written goals and plans. 13% had unwritten goals. 84% had no goals.

10 years later, the 3% students earned 10 times more than the other 97%¹ of the class combined.

The shortest punchline in advertisement packs the biggest blow. A few remarkable catchphrases or slogans have been permanently affixed to their brand names:

Yellow Pages: Let your fingers do the walking.

Red…

De Lin Show

Teacher | Blogger at showdeyang.com

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