November 2017

When Change Changes The World -Mental Model 059

Paradigm Shift

The usual or accepted way of doing something changes completely.


Example: Before 1859, the common belief was that people were created by God. Following Charles Darwin’s release of his theory of evolution in 1859, the paradigm has shifted  towards evolution.


Wisdom: “The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.” ― Albert Einstein


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How Many Drops Of Water Are In Lake Tahoe? -Mental Model 058

Fermi Problem

A question that seeks a fast, rough estimate of quantity which is either difficult or impossible to measure directly.


Example: Fermi problems are often known as back-of-the-envelope calculations, such as; How many drops of water are there in Lake Tahoe? Solving that problem requires an estimate of the volume of the drop, the volume of Lake Tahoe from its approximate dimensions and conversion of units to provide the answer.


Wisdom: “The first method for estimating the intelligence of a ruler is to look at the men he has around him.” ― Niccolò Machiavelli


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When Groupthink Goes Wrong -Mental Model 057


The desire for harmony or conformity in the group results in an irrational or dysfunctional decision-making outcome.


Example: In 1637, despite having little intrinsic value, the price of a single tulip bulb sold for more than 10 times the annual income of a skilled craftsman. The price rose only because everyone placed an irrational value on them.


Wisdom: “Whenever you find yourself on the side of the majority, it is time to pause and reflect.” — Mark Twain


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When Science Was Luck Not Science -Mental Model 056


The ability of an experiment or study to be duplicated.


Example: When PhD Brian Nosek and his team at the Center for Open Science attempted to reproduce 100 different psychology studies—only 39 were successfully replicated.


This demonstrates that a single scientific study does not prove something to be true—it must be reproduced.


Imagine conducting a coin tossing experiment. You have ten samples – ten tosses of the coin. It lands on heads every time. From the results you could infer that coins always land on heads. However, by trying to reproduce the ten tosses landing on heads, you will quickly find the results are not reproducible.


Wisdom: “All men make mistakes, but a good man yields when he knows his course is wrong, and repairs the evil. The only crime is pride.” ― Sophocles


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The Diffraction Pattern That Changed The World -Mental Model 055

Scientific Method

The systematic observation, measurement, and experiment, and the formulation, testing, and modification of a hypothesis.


Example: Let’s see how the scientific method was used to discover the structure of DNA.


Scientists had discovered the chemical composition of DNA and that is carried genetic information. But the question remained…


> Question: How is genetic information stored in DNA? What is the mechanism?


The scientists Pauling, Crick and Watson hypothesised that…


> Hypothesis: DNA has a helical (spiral) structure.


Let’s get some background info before we look at the prediction. An X-ray beam is used to view DNA because atoms are too small to be seen using a microscope.


A beam of X-ray radiation focused on an object and through to a photographic film on the far side will produce a series of spots on the film. Those spots are formed by the X-ray radiation diffracting off the structure they passed through.


The predication is…


> Prediction: If DNA had a helical structure then its X-ray diffraction pattern would be X-shaped.


> Experiment: Rosalind Franklin performed X-ray diffraction on DNA which produced an X-shaped photo.


> Analysis: When Watson saw the photo, he recognised the helical structure, which proved his hypothesis.


Wisdom: “Nullius in Verba / On no man’s word.” — Royal Society of London


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The Mysterious Disappearance Of Saudi Arabia’s Garden Of Eden -Mental Model 054

Second Order Effects

First order effects directly follow from a cause, while second order effects follow from first order effects.


Example: Imagine a line of dominoes. You knock the first one over—that’s the first order effect. Then the first domino knocks the second domino over—that’s the second order effect. And so on.


Off the coast of Saudi Arabia there is a small island country called Bahrain. A few decades ago, it was filled with lush greenery—an oasis said to be the site of the Garden of Eden. Now, that same land is a desert—because of second order effect.


How so? Bahrain is surrounded by a network of underground springs that fed the plant life. As Bahrain’s major city, Manama, became crowded, the country looked to expand its available land by excavating dirt from the centre of the island and depositing it on the coast—making more land available to build on. The new land was the first order effect. The second order effect was unintended—it caused the underground springs to dry up and the plant life disappeared.


Wisdom: “We are free to choose our actions, we are not free to choose the consequence of our actions.” — Stephen Covey


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You Won’t Believe How A Graduate Student Got Hired On Wall Street -Mental Model 053

Lateral Thinking

Solving problems through an indirect and creative approach, using reasoning that isn’t obvious and involving ideas that are not obtained through step-by-step logical thinking.


Example: A graduate student was trying to get into Investment banking, but couldn’t get a single interview. So he Googled the names of the senior executives at the firms he wanted to work, and spend $14 on Google ads that were shown when the executives searched for their own names. The ad said, “Hi, (Executive name), Googling yourself can be profitable. Hiring me is profitable too.” He now makes a 7 figure income on Wall Street.


Wisdom: “Creativity is just connecting things. When you ask creative people how they did something, they feel a little guilty because they didn’t really do it, they just saw something. It seemed obvious to them after a while. That’s because they were able to connect experiences they’ve had and synthesise new things.” — Steve Jobs


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Why Your Perspective Limits Your Vision -Mental Model 052

Maslow’s Hammer

If all you have is a hammer, everything looks like a nail.


Example: If you had $1 million to spend, a real-estate agent would tell you property is the best investment, a stock broker will tell you purchasing stocks is best, and a gambler would tell you horse 7 in race 2 is a sure thing.


Wisdom: “Prosperity is only an instrument to be used, not a deity to be worshipped.” ― Calvin Coolidge


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How Statistics Show Bias When It Doesn’t Exist -Mental Model 051

Simpson’s Paradox

A paradox in probability and statistics, in which a trend appears in different groups of data but disappears or reverses when these groups are combined.


Example: In 1973, graduate admissions to University of California, Berkeley, showed that men applying were more likely to be admitted than women. There appeared to be a gender bias.


But when examining the individual University departments, it appeared that six out of eighty-five departments were significantly biased against men, whereas only four were significantly biased against women. In fact, the pooled and corrected data showed a small but statistically significant bias in favor of women.


Wisdom: “Don’t cross a river if it is four feet deep on average.” ― Nassim Taleb


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Why Apple Sacrificed The Quality Of Its App Store -Mental Model 050

Strategy Tax

A company may sacrifice the competitiveness or quality of one product, in order to further the cause of another product.


Example: Apple has complete control over its iOS app store. While it may provide a better user experience by accepting more apps, Apple has rejected applications that directly compete with their own apps. They sacrifice the competitiveness of their platform – their app store, to protect their products- their Apple apps.


Wisdom: “You can have anything you want – you just can’t have everything you want.”


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