Correlations

Question 1

What is a correlation?

Answer 1

A test to see whether two variables are related.

Question 2

What is the difference between ‘correlation’ and ‘causation’?

Answer 2

Just because two things are related, does not mean that one is necessarily causing the other.

Question 3

What type of graphs are correlations displayed on?

Answer 3

Scatter graphs

Question 4

What is a ‘correlation coefficient’?

Answer 4

• A descriptive statistic with a numerical value between -1 and +1.

Question 5

What does a correlation coefficient demonstrate?

Answer 5

The strength and direction of a relationship.

Question 6

List each numerical correlation and their meaning.

Answer 6

+1, perfect positive correlation.

-1, perfect negative correlation.

0, no correlation.

+0.7 and above, strong correlation.

0.5 - 0.7, moderate correlation.

0.4 and below, weak correlation.

Question 7

List the 3 differences between correlational studies and experiments/tests of differences.

Answer 7

1. A correlational study has 2 DVs, whereas a test of difference has and IV and a DV.
2. A correlational study cannot show causation, but a test of difference can.
3. A correlation study needs to use variables which can both be put onto scales (ordinal variables) - a test of difference can use categorical data (nominal).

Question 8

What is a curvilinear correlation?

Answer 8

• Sometimes the relationship between co-variables might be curvilinear - meaning there is still a predictable relationship.
• However, there is an optimum point.