It’s week 11 of the English writing class. Time to learn about correlation and causation.
Plan for the Week
- review last week’s lesson
- last time to collect book title for book report
- attendance (5)
- review last week (5)
- argument with one sentence pattern
- short writing about the electric car and ketchup ad
- hypothesis sentence pattern
- the higher the income, the longer the life expectancy
What’s coming soon?
- quiz #2 – week 13
- book report due date: week 14, December 4/5
Main Lesson: Understanding Correlation and Causation
Step 1: What is a Correlation? (5)
There are two more more variables. They both change.
The variables seem to change together.
Perhaps, for example, the variables become bigger or smaller at the same time.
A correlation can often be described with a hypothesis sentence pattern (the one we studied last week).
There is one key point about correlations:
- the two variables seem to be connected but there is no proof of causation (cause and effect)
- there is no proof that one variable makes the other variable change
Step 2: What is Causation? (5)
There are two more more variables. They both change.
But one variable makes the other variable change.
The more pollution in the air, the more people get sick. Air pollution goes into people’s lungs and causes infection. That infection causes people to sneeze, cough and feel bad. When air pollution is bad, more people go to see the doctor.
In this example, we can understand that there is both a correlation and cause and effect connection between the amount of air pollution and the number of people who get sick.
There are two key points with causation:
- It shows WHAT things change or move.
- Causation also tells us WHY things change.
Look at these correlations. Do they talk about a good cause and effect connection?
- The more I sleep, the more I remember.
- The louder the music in a beer bar, the more beer people drink.
Step 3: Superstition, Myth and Crazy Ideas (10)
A: Why is there a bag of salt in front of your door?
B: To keep the evil spirits away.
A: Did it work?
B: Yes, we’ve had no bad luck since my mom put the salt near the door.
Superstition is the idea that there is some kind of special power in the world that we cannot see. However, if we do something, we can bring good or bad luck to people.
Superstition is a belief in a cause and effect relationship between two variables. But there is no causation. It might however be correlation.
Here are some examples:
- A baseball player does not change his socks when he is hitting the ball very well for many games. He thinks those socks bring him good luck and that luck makes him hit the ball well.
- In Korea, mothers do not serve seaweed soup for breakfast if a son or daughter has a test on that day.
Here is the basic sentence pattern of superstitions.
- A happens before B.
- Therefore, A causes B to happen.
Pair Work Practice (15)
Read these sentences. What is the argument? Does it suggest logical causation?
- I can’t believe I failed my chemistry test. I knew I should have worn my lucky sweatshirt to the test.
- Roosters crow just before the sun rises. Therefore, roosters crowing cause the sun to rise.
- Spinach can’t be good for me. It tastes terrible.
Step 4: Pair Work Practice (20)
Here is a pair work exercise. I want you to practice thinking about causation and correlation.
- Work in pairs.
- Look at a chart for one minute.
- Write one hypothesis sentence that summarizes the data.
- Name the variables.
- Answer this question: is this a correlation or causation? Explain why.
- Let’s do one picture together.
- Here is the practice question. first image.
Let’s do a drill.
By now, you should have a good understanding of correlation and causation. With that knowledge, can you understand the purpose of writing exercise #2?
Task Description (30)
Read the sentences below and look at the chart. For each question, I want you to do three things.
- Describe: What are the two variables (i.e. the things that change)?
- Understand: Express the idea as a correlation using the basic hypothesis sentence pattern.
- Analyze: Do you think there is a cause and effect relationship? Explain why, or why not, with reasons.
- Look at the students in this elementary school. The children with larger shoe sizes can speak English better than the kids with small shoe sizes.
- My students spend a lot of time in the library. I think they will get high test scores.
- Look at those girls over there. They are so thin. You know what? They all eat a big breakfast every morning.
- Look at the chart.
Write 3-5 correlations using the hypothesis sentence pattern. Then explain why each of them is a cause and effect relationship. If you need help, here are a few hints to get your thinking started:
- burning coal
- the ozone layer
- become rich
- dinosaurs became extinct
- can’t sleep at night
- high suicide rate
- too much time playing computer games
Here is what one student wrote about library time and test score.
The two variables are the time spent in the library and test scores. The more students spend time in the library, the higher the test score.
I think there is a cause and effect in this sentence because a library is a place for people to study and read books. So, if people spend a lot of time there they will likely spend most of their time studying or reading books and this will make them gain more knowledge and gaining more knowledge will lead them to a high score in tests.
This is very good for two reasons:
- Describe clearly the correlation with the hypothesis sentence pattern.
- Describe how the two things are connected in a few steps. The sentence is kind of long but we can understand the links.