Correlations

Question 1

What is a correlation?

Answer 1

A statistical, mathematical technique in which a researcher investigates an association between two variables (called co-variables)

Question 2

What does a correlation show?

Answer 2

The strength and direction of an association between two or more co-variables

Question 3

What is a positive correlation?

Answer 3

Refers to a relationship where the variables move in the same direction (increase in one = increase in another)

Question 4

What is a negative correlation?

Answer 4

Refers to a relationship on which an increase in one variable is accompanied by a decrease in another

Question 5

What is a zero correlation?

Answer 5

This means that there is no relationship between two variables

Question 6

What does a correlation hypothesis do? Give an example

Answer 6

It states the expected association between the co-variables

E.g. ‘There will be a positive correlation between age and beauty’

Question 7

What is a correlation coefficient? Explain how it works

Answer 7

A numerical measure of the strength and direction of the relationship between variables - it is between -1 and +1
-1 represents a perfect negative correlation and a +1 is a perfect positive correlation

Question 8

Explain the difference between an experiment and a correlation

Answer 8

An experiment shows cause and effect - a correlation doesn’t

Extraneous variables are controlled in an experiment where as correlations don’t control extraneous variables

An experiment manipulates an IV where as a correlation doesn’t

An experiment shows the difference between two variables where as a correlation shows a relationship between two factors

Question 9

What are the strengths of a correlation?

Answer 9

• Provides a precise quantifiable measure of how two variables are related
• May suggest ideas for future research
• Starting point to assess possible patterns between variables before committing to an experimental study
• Quick and economical - data is often pre-existing
• More ethical as there’s no manipulation of variables (correlation studies don’t have the issues concerning the right to withdraw, consent etc)

Question 10

What are the limitations of correlations?

Answer 10

• Lack of control of extraneous variables - they only tell us that the variables are related not WHY
• Cannot demonstrate cause and effect
• It may be that a 3rd variable/intervening variable has caused the relationship between the co-variables