論理的思考1 原因を明らかにする

Padlocks linked together

Too many conclusions can be attached to a single piece of data

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健全な論理を使うことは、上級英語コミュニケーションに不可欠で、会議や、会話、英語のテストなどで、理解する事、明快な解答をする事に役立ちます。原因と結果、その相関関係をこのレッスンで学習します。

Introduction

We will discuss how to build an argument using cause and effect, and how it can be confused with correlation.

Warm Up

A man points to a chart that shows how temperatures around the world have been rising over the past two centuries. The chart shows that at the same time, the number of people wearing traditional Japanese kimonos has been decreasing. Thus, he argues, the number of people wearing kimonos effects the global temperature, and the answer to global warming is to make kimonos popular again.

We can agree that he is completely incorrect, but why is he incorrect?

False Cause
Language

First we will talk about correlation and causation. What do these words mean? Try to think of some examples.

Correlation

Here are some commonly used patterns:

  • A and B are correlated.
  • There is a (weak/strong) correlation between A and B.

Causation

When discussing causation, it's common to use so, because (of), or therefore.

Be careful not to confuse cause and because.

  • Being out in the sun can cause a sunburn because of dangerous UV rays.
  • The cost of fuel dropped; therefore, airplane tickets got cheaper. This is a case of overhead costs dropping, which usually causes a drop in price for the end user.
Practice

Read and discuss these situations in terms of being a correlation or a causation. What information would you need to make the causation clear?

  • I want my favorite baseball team to win, so I'm wearing red underpants! Last time I wore them, my team won.
  • In Canada, immigration from Ontario to Alberta increased. Soon after, the number of people receiving welfare in Alberta increased. Therefore, the increased immigration caused the increased welfare rolls.

Now, choose a question below and make a strong case for causation:

  1. Does expensive equipment improve your performance in a hobby?
  2. If the economy goes down, does that mean sales of electronics will also decrease?
  3. Does living in a big city affect your stress level?