3 ways to make better decisions -- by thinking like a computer | Tom Griffiths

翻译人员: jacks peng

If there's one city in the world

如果世界上有个城市

where it's hard to find a place to buy or rent,

很难买房或者租房，

it's Sydney.

它就是悉尼。

And if you've tried to find a home here recently,

如果你最近在找地方安家，

you're familiar with the problem.

你一定对此深有感触。

Every time you walk into an open house,

每次你走进一个对公众开放的待售房，

you get some information about what's out there

就会了解到市场上

and what's on the market,

相关的信息，

but every time you walk out,

但每次你从房子里走出去，

you're running the risk of the very best place passing you by.

就冒着错过最好房子的风险。

So how do you know when to switch from looking

那么你怎么知道何时从单纯的寻找，

to being ready to make an offer?

转向准备出手呢？

This is such a cruel and familiar problem

这个如此残酷和熟悉的问题

that it might come as a surprise that it has a simple solution.

却可能有个让人惊讶的简单解决方案。

37 percent.

37%。

(Laughter)

（笑声）

If you want to maximize the probability that you find the very best place,

如果你想要最大化找到最佳居所的概率，

you should look at 37 percent of what's on the market,

就应该把市场上37%的房子看完，

and then make an offer on the next place you see,

然后在你看到的下一个地方出价，

which is better than anything that you've seen so far.

这个地方要比你目前看过的都要更好。

Or if you're looking for a month, take 37 percent of that time --

或者假如你要花一个月的时间 寻找，拿出37%的时间——

11 days, to set a standard --

11天，来建立标准——

and then you're ready to act.

然后就可以准备行动了。

We know this because trying to find a place to live

我们知道这点是因为尝试找到好的居所

is an example of an optimal stopping problem.

是“最优停止问题”的一个案例。

A class of problems that has been studied extensively

这是数学家和计算机科学家

by mathematicians and computer scientists.

广泛研究的一类问题。

I'm a computational cognitive scientist.

我是个计算认知科学家。

I spend my time trying to understand

我把时间都花在理解

how it is that human minds work,

人们的头脑如何工作上面，

from our amazing successes to our dismal failures.

从我们的惊人成就，到令人叹息的失败。

To do that, I think about the computational structure

为此，我会考虑日常生活中

of the problems that arise in everyday life,

出现的问题的计算结构，

and compare the ideal solutions to those problems

并把这些问题的理想解决方案

to the way that we actually behave.

与我们实际会做出的行为相比较。

As a side effect,

作为副产品，

I get to see how applying a little bit of computer science

我还发现了如何利用一点计算科学知识

can make human decision-making easier.

让人类更轻松地做出决策。

I have a personal motivation for this.

对此，我有一个私人动机。

Growing up in Perth as an overly cerebral kid ...

作为在珀斯长大的一个过度理智的孩子…

(Laughter)

（笑声）

I would always try and act in the way that I thought was rational,

我总试着用我觉得理性的方式行事，

reasoning through every decision,

对每一个决定进行推理，

trying to figure out the very best action to take.

想要算出要采取的最佳行动。

But this is an approach that doesn't scale up

但这种方法无法扩展到

when you start to run into the sorts of problems

你开始在成人生活中

遇到的各种问题。

that arise in adult life.

At one point, I even tried to break up with my girlfriend

有一次，我甚至想和我女友分手，

because trying to take into account her preferences as well as my own

只因为我在考虑如何在 她的喜好和我的喜好中

and then find perfect solutions --

寻找最佳的折中方案——

(Laughter)

（笑声）

was just leaving me exhausted.

而最后却搞得我精疲力尽。

(Laughter)

（笑声）

She pointed out that I was taking the wrong approach

她指出我解决这个问题的方法

to solving this problem --

是错误的——

and she later became my wife.

后来她成为了我的妻子。

(Laughter)

（笑声）

（鼓掌）

(Applause)

Whether it's as basic as trying to decide what restaurant to go to

不管是去哪家餐厅这样的小决策，

or as important as trying to decide who to spend the rest of your life with,

还是重要到需要决定与谁度过余生，

human lives are filled with computational problems

人类的生活总是面临着各种

that are just too hard to solve by applying sheer effort.

很难靠单纯的努力来解决的计算问题。

For those problems,

面对这些问题，

it's worth consulting the experts:

咨询专家是个不错的选择：

computer scientists.

我说的是计算机科学家。

(Laughter)

（笑声）

When you're looking for life advice,

当你寻找生活中的建议时，

computer scientists probably aren't the first people you think to talk to.

计算机科学家可能不是你首选的谈话对象。

Living life like a computer --

像电脑一样生活——

stereotypically deterministic, exhaustive and exact --

一成不变的确定性，详尽和准确——

doesn't sound like a lot of fun.

听起来挺无趣的。

But thinking about the computer science of human decisions

但研究人类决策的计算机科学

reveals that in fact, we've got this backwards.

揭示了这样一个事实，我们把它搞反了。

When applied to the sorts of difficult problems

当处理人们生活中遇到的

that arise in human lives,

各种难题时，

计算机解决这些问题的方式

the way that computers actually solve those problems

looks a lot more like the way that people really act.

跟人类真实行为非常相似。

Take the example of trying to decide what restaurant to go to.

拿试图决定去哪个餐厅为例。

This is a problem that has a particular computational structure.

这个一个有着特定计算结构的问题。

You've got a set of options,

你有一组选项，

you're going to choose one of those options,

需要在这些选项中选择一个，

and you're going to face exactly the same decision tomorrow.

并且明天你将会面对同样的决定。

In that situation,

在那种情况下，

you run up against what computer scientists call

你遇到了计算机科学中所谓的

“探索与利用的权衡”。

the "explore-exploit trade-off."

You have to make a decision

你需要在

about whether you're going to try something new --

尝试新的——

exploring, gathering some information

即探索，收集

你将来能够使用的信息——

that you might be able to use in the future --

or whether you're going to go to a place that you already know is pretty good --

或者去那个已知的非常好的 地方之间做出选择——

exploiting the information that you've already gathered so far.

利用你目前已经收集到的信息。

The explore/exploit trade-off shows up any time you have to choose

“探索与利用的权衡”出现在每一次

between trying something new

你需要在尝试新的

and going with something that you already know is pretty good,

和已知的优质体验之间作出选择，

whether it's listening to music

不管是听音乐

还是决定要跟谁聚会。

or trying to decide who you're going to spend time with.

It's also the problem that technology companies face

科技公司也会面临同样的问题，

when they're trying to do something like decide what ad to show on a web page.

当他们需要决定比如应该在 网页上展示什么广告时。

他们是应该展现新广告，并从中学习呢，

Should they show a new ad and learn something about it,

还是给你展现那个

or should they show you an ad

他们已经知道你很可能会点击的广告呢？

that they already know there's a good chance you're going to click on?

Over the last 60 years,

在过去60年中，

computer scientists have made a lot of progress understanding

计算机科学家在理解探索与利用的权衡

the explore/exploit trade-off,

上面取得了很大的进展，

and their results offer some surprising insights.

而且他们的研究给出了 一些让人惊讶的洞察。

When you're trying to decide what restaurant to go to,

当你在决定去哪家餐厅时，

the first question you should ask yourself

你应该问自己的第一个问题是，

is how much longer you're going to be in town.

你还要在城里呆多久。

If you're just going to be there for a short time,

如果你在那里只是短暂的停留，

then you should exploit.

那么你就应该享受（“利用”）。

There's no point gathering information.

收集信息没有意义。

Just go to a place you already know is good.

只需要直接去那家你喜欢的餐厅。

But if you're going to be there for a longer time, explore.

但如果你会呆很长的时间， 那就花点时间“探索”。

Try something new, because the information you get

试试新的餐厅，因为你收集的信息

is something that can improve your choices in the future.

可以在未来优化你的选择。

The value of information increases

有价值的信息增多了，

the more opportunities you're going to have to use it.

你将来使用它的机会也越多。

This principle can give us insight

这个原则也可以帮助我们深入理解

into the structure of a human life as well.

人类生命的结构。

Babies don't have a reputation for being particularly rational.

婴儿并不是理性的代名词。

They're always trying new things,

他们总在尝试新东西，

and you know, trying to stick them in their mouths.

比如，什么东西都想往嘴里塞。

But in fact, this is exactly what they should be doing.

事实上，这一行为非常合理。

They're in the explore phase of their lives,

他们正处于生命中的探索阶段，

and some of those things could turn out to be delicious.

这些东西可能正好是美味的。

At the other end of the spectrum,

相反，

the old guy who always goes to the same restaurant

老人总是去同样的餐厅，

and always eats the same thing

吃同样的东西，

isn't boring --

这跟单调的行为无关——

he's optimal.

只是最优选择罢了。

(Laughter)

（笑声）

He's exploiting the knowledge that he's earned

他正在利用一生中

through a lifetime's experience.

所积累的知识。

More generally,

更一般的情况下，

knowing about the explore/exploit trade-off

了解“探索与利用的权衡”这一原则，

can make it a little easier for you to sort of relax and go easier on yourself

可以让你在尝试做选择时

感到更轻松。

when you're trying to make a decision.

你不需要每晚都去最佳餐厅。

You don't have to go to the best restaurant every night.

Take a chance, try something new, explore.

找个机会，试试新的，探索一番。

You might learn something.

你可能会有新的发现。

And the information that you gain

你获取的信息

会比一顿美味的晚餐更有价值。

is going to be worth more than one pretty good dinner.

Computer science can also help to make it easier on us

计算机科学也可以帮助我们 在家和工作场所的其他地方

in other places at home and in the office.

更轻松地做出决策。

If you've ever had to tidy up your wardrobe,

如果你有需要整理衣橱的经历，

you've run into a particularly agonizing decision:

你就已经遇到了一个非常痛苦的决定：

你得决定哪些东西要留下来，

you have to decide what things you're going to keep

and what things you're going to give away.

哪些东西要丢掉。

Martha Stewart turns out to have thought very hard about this --

玛莎 · 斯图尔特曾经 非常认真地思考过这个问题——

(Laughter)

（笑声）

and she has some good advice.

而且她有一些好建议。

She says, "Ask yourself four questions:

她说，“问你自己4个问题：

How long have I had it?

我拥有这件东西多长时间了？

Does it still function?

它仍然完好吗？

Is it a duplicate of something that I already own?

我还有其他类似的东西吗？

And when was the last time I wore it or used it?"

我上次穿它或用它是什么时候？”

But there's another group of experts

但还有另一群专家

who perhaps thought even harder about this problem,

对这个问题的思考更加深入，

and they would say one of these questions is more important than the others.

他们会说，其中一个问题 比其他问题更重要。

Those experts?

这些专家是谁呢？

The people who design the memory systems of computers.

就是设计计算机内存系统的人。

Most computers have two kinds of memory systems:

大部分电脑有两种类型的内存系统：

a fast memory system,

快速存储系统，

like a set of memory chips that has limited capacity,

如一组容量有限的内存芯片，

because those chips are expensive,

因为这些芯片非常昂贵，

and a slow memory system, which is much larger.

还有慢速存储系统，但容量更大。

In order for the computer to operate as efficiently as possible,

为了让电脑工作效率尽可能高，

you want to make sure

你想要确保

that the pieces of information you want to access

你需要获取的一段信息

are in the fast memory system,

在快速存储系统中，

这样就可以快速获取它们。

so that you can get to them quickly.

每次你获取一段信息，

Each time you access a piece of information,

该信息就会进入快速存储中，

it's loaded into the fast memory

and the computer has to decide which item it has to remove from that memory,

而电脑需要决定哪些信息 需要从那个存储中移除，

because it has limited capacity.

因为它的容量有限。

Over the years,

多年来，

computer scientists have tried a few different strategies

计算机科学家试了几种不同的策略

for deciding what to remove from the fast memory.

来决定应该从快速存储中移除什么。

他们试过比如随机选择，

They've tried things like choosing something at random

or applying what's called the "first-in, first-out principle,"

或是应用“先进先出”原则，

which means removing the item

意思是移除

which has been in the memory for the longest.

被储存时间最长的信息。

But the strategy that's most effective

但最有效的策略是，

focuses on the items which have been least recently used.

聚焦那些最近最少被使用的条目。

This says if you're going to decide to remove something from memory,

也就是说，如果你打算从存储中删掉点什么，

就应该移除距离最近一次访问最久的内容。

you should take out the thing which was last accessed the furthest in the past.

And there's a certain kind of logic to this.

这显然是合乎逻辑的做法。

If it's been a long time since you last accessed that piece of information,

假如你上次访问那段信息 是在很久以前了，

it's probably going to be a long time

那么你也很可能在很久之后才会

before you're going to need to access it again.

再次需要访问这段信息。

Your wardrobe is just like the computer's memory.

你的衣柜就像计算机的内存。

You have limited capacity,

衣橱的容量有限，

and you need to try and get in there the things that you're most likely to need

你需要尽量把最常用的东西放进去，

so that you can get to them as quickly as possible.

这样你就会尽可能快速地得到它。

Recognizing that,

认识到这点，

maybe it's worth applying the least recently used principle

也许值得应用“最近最少使用”原则

来管理你的衣柜。

to organizing your wardrobe as well.

如果我们回到玛莎的四个问题，

So if we go back to Martha's four questions,

计算机科学家会说，在这些问题中，

the computer scientists would say that of these,

the last one is the most important.

最后一个是最重要的。

This idea of organizing things

这种管理东西的方法，

so that the things you are most likely to need are most accessible

也就是让你最可能需要的东西最唾手可得，

can also be applied in your office.

也可以应用在你的工作中。

The Japanese economist Yukio Noguchi

日本经济学家野口勇

actually invented a filing system that has exactly this property.

就发明了一个拥有该属性的文件系统。

He started with a cardboard box,

他从一个纸箱开始，

and he put his documents into the box from the left-hand side.

然后从左手边把文件放进盒子。

Each time he'd add a document,

每次他增加一个文件，

he'd move what was in there along

他会把里面的东西依次移动，

再把那个文件放在盒子的左手边。

and he'd add that document to the left-hand side of the box.

每次他需要看文件，就会把它取出来，

And each time he accessed a document, he'd take it out,

consult it and put it back in on the left-hand side.

用完之后放到左手边的位置。

As a result, the documents would be ordered from left to right

这样一来，文件就会根据最近使用的情况

by how recently they had been used.

从左到右排序。

And he found he could quickly find what he was looking for

他发现只要沿着盒子的

by starting at the left-hand side of the box

左边到右边搜索，

就可以快速找到他要找的文件。

and working his way to the right.

Before you dash home and implement this filing system --

在你赶回家尝试搭建这个文件系统前——

(Laughter)

（笑声）

it's worth recognizing that you probably already have.

值得注意的是，你可能已经拥有它了。

(Laughter)

（笑声）

That pile of papers on your desk ...

就是你桌上的那堆文件…

typically maligned as messy and disorganized,

通常被认为是凌乱无序的

a pile of papers is, in fact, perfectly organized --

这堆文件，实际上 已经经过了完美的整理——

(Laughter)

（笑声）

as long as you, when you take a paper out,

只要你把一张纸抽出来，

put it back on the top of the pile,

用完再放回到那堆文件上面，

then those papers are going to be ordered from top to bottom

这些文件就会从上到下

by how recently they were used,

根据最近使用的原则排序，

你就很可能在那堆文件中从上到下

and you can probably quickly find what you're looking for

by starting at the top of the pile.

快速找到你要找的东西。

Organizing your wardrobe or your desk

整理你的衣柜或书桌

are probably not the most pressing problems in your life.

可能不是你生活中最紧迫的问题。

Sometimes the problems we have to solve are simply very, very hard.

有时候我们需要解决的问题非常非常难。

But even in those cases,

但即便在这些案例中，

computer science can offer some strategies

计算机科学也可以提供一些策略

and perhaps some solace.

和些许安慰。

The best algorithms are about doing what makes the most sense

最好的算法是在最短的时间内

in the least amount of time.

做最合理的事情。

When computers face hard problems,

当电脑面对难题时，

they deal with them by making them into simpler problems --

会把它分解为简单问题——

by making use of randomness,

通过利用随机性，

by removing constraints or by allowing approximations.

消除约束或允许近似。

Solving those simpler problems

解决这些简单问题

can give you insight into the harder problems,

可以让你洞察更难的问题，

and sometimes produces pretty good solutions in their own right.

而且有时会产生很好的解决方案。

Knowing all of this has helped me to relax when I have to make decisions.

知道所有这些知识可以帮助 我们在做决定时倍感轻松。

You could take the 37 percent rule for finding a home as an example.

拿37%的原则来找房子就是一个例子。

There's no way that you can consider all of the options,

你根本不可能考虑到所有的选项，

so you have to take a chance.

所以你必须碰碰运气。

And even if you follow the optimal strategy,

即便你遵循了最优策略，

you're not guaranteed a perfect outcome.

也无法保证得到最佳结果。

If you follow the 37 percent rule,

如果你遵循37%原则，

the probability that you find the very best place is --

找到最佳居所的概率是——

funnily enough ...

这就相当有趣了...

(Laughter)

（笑声）

37 percent.

37%。

You fail most of the time.

你大部分时间都未能如愿。

But that's the best that you can do.

但是你已经尽力了。

Ultimately, computer science can help to make us more forgiving

最终，计算机科学可以帮我们更宽容地

of our own limitations.

面对自己的局限性。

You can't control outcomes, just processes.

你无法控制结果，只能调整方法。

And as long as you've used the best process,

只要你使用了最好的方法，

you've done the best that you can.

就已经尽了最大的努力。

Sometimes those best processes involve taking a chance --

有时候，最好的方法就是抓住机会——

not considering all of your options,

不去考虑你的所有选项，

or being willing to settle for a pretty good solution.

或者愿意接受一个很好的解决方案。

These aren't the concessions that we make when we can't be rational --

这些不是我们在无法进行 理性思考时做的让步——

they're what being rational means.

它们就是理性的意义。

Thank you.

谢谢。

（鼓掌）

(Applause)