Statistics in Schools - Why Statistics?

美國國家普查局（United States Census Bureau）發佈的統計學科普小視頻

All right. Why statistics?
Statistics: the practice or science of collecting and analyzing numerical data in large quantities.

Why study statistics at all? Why do we have a federal statistical system? Why a Census Bureau? What good is the study of statistics?

To answer this question, let's first talk about something else.
Why a microscope?
Well, a microscope is used for studying things that are, as the name may imply, microscopic.
Microscopic: so small or fine as to be invisible or indistinguishable without the use of a microscope.

You need to look at something that's really, really tiny, too small for your eye to see. And you blow it up to a screen about yay big. This turns out to be really, really handy. If you want to study cells, for example, like bacteria. You want to understand food poisoning, you want to understand disease, you want to understand how viruses spread, you got to be able to actually look at them, to see them. If you can understand how big they are, how small they are, what their shapes are, what their form is. If you can get the form, you can get the function and you can get some understanding. You want to build a microchip? You need a microscope.

Now, that means that a microscope is really, really useful for looking at things that are too small. Now, let's consider the kinds of questions that we answer with statistics.
We talk about things like the population of the United States. The population of the United States. In 2010, there were 308 million people in the United States. You can't possibly know everyone. You can't talk to... you as a person, you don't have enough time in your life to sit down with everybody and learn their story.

But, you know, every 10 years or so, we at the Census Bureau ask a few questions of everybody.
Age, sex, birth, where you live.
These are important things to know. And with just those few questions, we can learn an enormous amount. You want to know where the hospitals go? You need to know what cities have a large aging population. You want to know where the schools go? You need to know where the cities and what neighborhoods have a lot of really young people.

These kinds of questions, and it's all kinds of things. You know, birth rates, death rates. Want to understand the labor force? That's a statistical question. You want to understand employment, you want to understand earnings, you want to understand national earnings. You want to understand these questions, accident rates, all kinds of things that we publish statistics on, that we measure statistics, they're all things that are too big to see at one time. They're too big for your eye to see.
308 million people, all of different ages, all different sex. We've got accidents happening spread out across a country of literally millions of square miles. It's too big to take in.

But, aha! A federal statistical system, statistics, we can take a slice of that country. Delicious.
We can take a slice of the United States of America, and we can shrink it down to a screen about yay big.
You know, I got a bunch of them back here.

When you can take a big thing and shrink it down small enough to study, to understand, or at least part of it, that's useful. That's statistics.
So you want to understand something that's too small, like a cell or a microchip, you need to blow it up, you use a microscope.
Statistics is a macroscope.
That's why statistics.

为什么要学统计学？
为什么要学习统计学呢？为什么我们有联邦统计系统？为什么有普查局？研究统计学有什么好处？

要回答这个问题，我们先谈谈别的东西。
为什么要用显微镜？
嗯，显微镜是用来研究那些，顾名思义，微观的东西。
微观：小到或精细到没有显微镜就看不见或无法分辨。

你需要观察一些非常非常微小的东西，小到你的眼睛都看不见。然后你把它放大到这么大的屏幕上。这其实非常非常方便。如果你想研究细胞，比如细菌。你想了解食物中毒，你想了解疾病，你想了解病毒如何传播，你就必须能够真正地观察它们，看到它们。如果你能了解它们有多大、多小，它们的形状是什么，它们的形态是什么。如果你能了解形态，你就能了解功能，你就能获得一些理解。你想制造微芯片？你就需要一个显微镜。

所以，这意味着显微镜对于观察太小的东西真的非常有用。现在，让我们来思考一下我们用统计学回答的那些问题。
我们谈论像美国人口这样的事情。
美国的人口。2010年，美国有3.08亿人。你不可能认识每一个人。你不可能和……作为一个人，你一生中没有足够的时间和每个人坐下来了解他们的故事。

但是，你知道，大概每10年，我们普查局会向每个人问几个问题。
年龄、性别、出生日期、你住在哪里。
这些是需要了解的重要事情。仅仅通过这几个问题，我们就能学到非常多的东西。你想知道医院该建在哪里？你需要知道哪些城市有大量的老龄人口。你想知道学校该建在哪里？你需要知道哪些城市和社区有很多非常年轻的人。

这类问题，以及各种各样的事情。你知道，出生率、死亡率。想了解劳动力？这是个统计问题。你想了解就业，你想了解收入，你想了解国民收入。你想了解这些问题，事故率，我们发布的各种统计数据，我们测量的统计数据，它们都是些大到无法一次性看到全貌的东西。它们大到你的眼睛无法看到。3.08亿人，年龄各不相同，性别各异。事故发生在遍布数百万平方英里国土的各个地方。它太大了，无法尽收眼底。

但是，一个联邦统计系统，统计学，我们可以取这个国家的一个切片。真美味。我们可以取美利坚合众国的一个切片，然后我们可以把它缩小到这么大的屏幕上。你看，我身后就有一堆。

当你可以把一个大的东西缩小到足以研究、足以理解的程度，或者至少是它的一部分时，那是非常有用的。那就是统计学。
所以，你想了解一些太小的东西，比如细胞或微芯片，你需要把它放大，你使用显微镜。统计学就是一个宏观镜。这就是为什么要学统计学。