Correlation 2

Question 1

What’s a limitation of scattergrams?

Answer 1

Space consuming
The correlation coefficient fixes this: single numerical index

Question 2

What is the Pearson correlation?

Answer 2

The closeness of the fit of the points of the scattergram to the best fitting line straight through those points
Information about whether the scattergram’s slope is positive or negative
Useful for when you have several variables, so many scattergrams aren’t needed

Question 3

What’s an advantage of using Pearson correlation?

Answer 3

More concise than a scattergram

Question 4

What is the correlation coefficient?

Answer 4

How much variance two variables have in common
You need to square the coefficient to know much much variance is shared
This is known as coefficient of determination

Question 5

How do you interpret the correlation coefficient?

Answer 5

As the correlation coefficient gets smaller, the amount of variance shared between 2 variables declines