unit10 The Art of Smart Guessing 巧妙猜测的艺术

The Art of Smart Guessing

Several years ago, interviewing candidates for a job, I grew tired of asking "What experience do you have?" So I decided¹ on a one-question quiz to find out how resourceful a thinker the new hire might be. Here it is:

You are on a yacht sailing the Pacific Ocean. Your navigator announces you are over the deepest point, the Mariana Trench². Just then, a clumsy guest accidentally drops a 12-pound cannonball, over the side. How long will it take for the cannonball to reach the bottom of the ocean!

Before reading on, please try to solve this yourself--paying special attention to how you might solve it.

Did you make a completely wild guess because "there wasn't enough information"? Did you get too bogged³ down in the details trying to come up with the "exactly right" answer? Or did you zero in on the two most important problems--how deep is the Mariana Trench and how fast might a cannonball fall through the water-- then hazard a guesstimate?

Most of my candidates simply made a wild guess, thinking that if they couldn't be 100-percent right, there was no use trying to be 95-percent right. Rarely was someone willing to risk an approximation.

What does this have to do with business or creativity? A great deal. In the real world, we frequently need to make decisions when the full information does not exist. From what foods we eat to how to raise our kids, creative people must think for themselves. There may not be the time or the money to make sure of all your decisions. Your best guess will often be the best you can do.

Suppose, for example, you've been asked to write a marketing⁴ plan for a new telephone device that will send your name, company, address and telephone number to a visual display or printer on another person's phone. In addition to conventional outlets⁵ like mass merchandisers and electronics stores, you'd like to know the number of "phone stores" in the United States. Unfortunately, this figure is not available, either from market-research houses or from the U.S. government. What do you do?

One solution would be to go to your local library, pull out a few phone directories from around the country, turn to the Yellow Pages and start counting. You could then guesstimate how many stores there were nationwide, based on the number of stores per 100,000 people in each of the cities you counted. This, by the way, is exactly what a marketing consultant⁶ I know did for a large telecommunications client.

The question about phone stores was an example of what scientists call a Fermi problem, named after Nobel Prize-winning physicist⁷ Enrico Fermi , who used problems such as this to teach his students how to think for themselves. A Fermi problem does not contain all the information you need to solve it precisely⁸.

Fermi is said to have once asked his university students how many piano tuners there were in Chicago. To answer the question, he recommended breaking it down into smaller, more manageable questions , and then having the courage to make some guesses and assumptions. How many people live in Chicago? Three million would be a reasonable estimate. How many people per family? Assume an average of four. How many families own pianos? Say one out of three. Then there are about 250,000 pianos in Chicago. How often would each be tuned¹⁰? Maybe once every five years. That makes 50,000 tunings a year. How many pianos can one tuner tune⁹ in a day? Four? And how many in a year? Assuming 250 working days, one tuner can handle 1,000 pianos a year.

So there's work for approximately 50 piano tuners in Chicago-- which; as it turns out, is reasonably close to the actual number in the Yellow Pages.

Why was guesswork so accurate? The law of averages is partly responsible. At any point, your assumptions may be too high or too low. But because of the law of averages, your mistakes, will frequently balance out.

Here's another puzzle. You probably already know that black absorbs the most heat, while white reflects the most. But what about other colors in between? How could you find the answer? Hint: it's wintertime, but not too cold.

Ben Franklin's solution was elegant. He simply laid broadcloth samples of various colors on the snow on a sunny morning. "In a few hours," he reported, "the black, being warmed most by the sun, was sunk so low as to be below the stroke of the sun's rays; the dark blue, almost as low; the lighter¹¹ blue not quite so much as the dark; the other colors, less as they were lighter, and the quite white remained on the surface of the snow, not having entered it at all."

One of my favorite "guesstimators" is Weston, Conn., inventor Stan Mason, who developed microwave cookware specially¹² designed to position food in the best spot for cooking.

To do this, Mason needed to know where the microwave's "hot spots were -- the place where the rays hit the food with the highest intensity¹³. To find out, he put shelves of unpopped popcorn¹⁴ kernels¹⁵ in the microwave and watched to see which kernels popped first. He discovered a pattern in the oven's hottest rays: they weren't in the corners or at the center, but in the shape of a mushroom cloud.

Then he designed cooking dishes to fit the pattern. He had come up with a resourceful way to approximate the answer rather than using scientifically sophisticated testing equipment.

Fermis would have approved.

By the way, the Mariana Trench is about six nautical¹⁶ miles deep, and a cannonball drops at a rate of ten feet per second. So it took the cannonball about an hour to reach the bottom of the trench.

Could this be guessed? If you know that Earth's highest point Mount Everest, is 29,000 feet, you might reasonably conclude that its lowest point would be close to the same distance. Then you might imagine that a heavy object would take one second to fall through the water of a 10-foot-deep swimming pool. These estimates would bring you close enough to the correct answer.

1 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

2 trench   

n./v.(挖)沟，(挖)战壕

参考例句：

• The soldiers recaptured their trench.兵士夺回了战壕。
• The troops received orders to trench the outpost.部队接到命令在前哨周围筑壕加强防卫。

3 bogged   

adj.陷于泥沼的v.（使）陷入泥沼， （使）陷入困境( bog的过去式和过去分词 )；妨碍，阻碍

参考例句：

• The professor bogged down in the middle of his speech. 教授的演讲只说了一半便讲不下去了。 来自《现代英汉综合大词典》
• The tractor is bogged down in the mud. 拖拉机陷入了泥沼。 来自《简明英汉词典》

4 marketing   

n.行销，在市场的买卖，买东西

参考例句：

• They are developing marketing network.他们正在发展销售网络。
• He often goes marketing.他经常去市场做生意。

5 outlets   

n.出口( outlet的名词复数 )；经销店；插座；廉价经销店

参考例句：

• The dumping of foreign cotton blocked outlets for locally grown cotton. 外国棉花的倾销阻滞了当地生产的棉花的销路。 来自《简明英汉词典》
• They must find outlets for their products. 他们必须为自己的产品寻找出路。 来自《现代汉英综合大词典》

6 consultant   

n.顾问；会诊医师，专科医生

参考例句：

• He is a consultant on law affairs to the mayor.他是市长的一个法律顾问。
• Originally,Gar had agreed to come up as a consultant.原来，加尔只答应来充当我们的顾问。

7 physicist   

n.物理学家，研究物理学的人

参考例句：

• He is a physicist of the first rank.他是一流的物理学家。
• The successful physicist never puts on airs.这位卓有成就的物理学家从不摆架子。

8 precisely   

adv.恰好，正好，精确地，细致地

参考例句：

• It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
• The man adjusted very precisely.那个人调得很准。

9 tune   

n.调子；和谐，协调；v.调音，调节，调整

参考例句：

• He'd written a tune,and played it to us on the piano.他写了一段曲子，并在钢琴上弹给我们听。
• The boy beat out a tune on a tin can.那男孩在易拉罐上敲出一首曲子。

10 tuned   

adj.调谐的，已调谐的v.调音( tune的过去式和过去分词 )；调整；（给收音机、电视等）调谐；使协调

参考例句：

• The resort is tuned in to the tastes of young and old alike. 这个度假胜地适合各种口味，老少皆宜。
• The instruments should be tuned up before each performance. 每次演出开始前都应将乐器调好音。 来自《简明英汉词典》

11 lighter   

n.打火机，点火器；驳船；v.用驳船运送；light的比较级

参考例句：

• The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
• The lighter works off the car battery.引燃器利用汽车蓄电池打火。

12 specially   

adv.特定地；特殊地；明确地

参考例句：

• They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
• The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。

13 intensity   

n.强烈，剧烈；强度；烈度

参考例句：

• I didn't realize the intensity of people's feelings on this issue.我没有意识到这一问题能引起群情激奋。
• The strike is growing in intensity.罢工日益加剧。

14 popcorn   

n.爆米花

参考例句：

• I like to eat popcorn when I am watching TV play at home.当我在家观看电视剧时，喜欢吃爆米花。
• He still stood behind his cash register stuffing his mouth with popcorn.他仍站在收银机后，嘴里塞满了爆米花。

15 kernels   

谷粒( kernel的名词复数 )； 仁； 核； 要点

参考例句：

• These stones contain kernels. 这些核中有仁。
• Resolving kernels and standard errors can also be computed for each block. 还可以计算每个块体的分辨核和标准误差。

16 nautical   

adj.海上的，航海的，船员的

参考例句：

• A nautical mile is 1,852 meters.一海里等于1852米。
• It is 206 nautical miles from our present location.距离我们现在的位置有206海里。