Logical thinking 3 Using data

Relationships between data points can be complex

Using sound logic is vital for advanced communication. It will also help you answer questions clearly in meetings, presentations and conversation, as well as get better scores on logical aspects of English speaking tests. This lesson is about how to use data.


Gathering data is an important part of logical thinking, but it is crucial to keep in mind that not all data are equal in validity or relevance.  In order to use sound logic, weeding out any erroneous or irrelevant data is an unavoidable part of the process.

Warm Up: 

A man pointed to research showing that of the five countries where Sugarette drinks sell the most units, four of them are in the top ten healthiest countries on Earth, therefore drinking Sugarette leads to a healthy lifestyle.

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


Incomplete evidence can be used to back up any kind of argument. This is called cherry-picking data.

I heard that living near a wind farm is bad for your health, and I did a Google search about it, and found hundreds of articles saying it's true!

To discuss this, we can say:

  • While it's true that there are hundreds of people on the internet that say wind farms are bad for your health, there are also millions of articles on the internet as a whole, so we can find articles on many, many topics. We also have to look at the writers—are they trustworthy?

Can you think of anything else to discuss the credibility of this argument? Here are some useful phrases to help you:

  • While it's true that __A__, __B___ is also true.
  • We also have to look at/ consider/ think about/ take a look at...

First, let's discuss this politician's claim: 

"The economy is getting worse, and good people are unable to find work. I talked to a young man named Jim, and he's been out of work for six months. I talked to a woman named Sheryl who told me she was laid off last year. Every day, I talk to people who are having trouble!"

Is this argument valid? What would you need to make a stronger argument about the economy?

Second, let's consider these statistics:

New York roads are so dangerous! In 2015, New York saw 966 traffic related deaths! While in Wyoming, there were only 190 in the same year.

Is this argument valid? What would you need to make a stronger argument about road safety?