Correlation

Question 1

What are the three types of correlation ?

Answer 1

• positive
• negative
• zero

Question 2

What is correlation ?

Answer 2

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

Question 3

What are co-variables ?

Answer 3

Variables being measured for an association using a correlation

Question 4

What is a correlation co-efficient ?

Answer 4

-1 = is when 2 variables vary inversely (negative correlation)
+1 = when 2 variables vary together (positive correlation)
The sign tells you the direction
The number tells you the strength of correlation

Question 5

What are the differences between correlation studies and experiments ?

Answer 5

Correlation studies:
- cannot reliably predict cause and effect
- predicts a relationship between variables rather than a difference
- lack of control over variables
- Intervening variables

Experiments:
- Have independent and dependent variables
- Observe cause and effect
- Controls and environment can be set up

Question 6

What are the strengths of correlation ?

Answer 6

• Useful for preliminary research to identify a link for future research
• Useful for sensitive/ unethical research (no deliberate manipulation of variables)

Question 7

What are the limitations for correlation ?

Answer 7

• does not identify a casual relationship
• problem of a third variables