Correlation

Question 1

What is correlation?

Answer 1

A correlation is a statistical measurement of the relationship between two or more co-variables
Correlation illustrates the strength and direction of an association between co-variables
Correlations are plotted on a scattergram: one co-variable forms the x axis and the other on the y axis

Question 2

What is the difference between experiments and correlations?

Answer 2

In experiments, the researchers manipulate the IV in order to measure the effect of the DV
In correlations, there is no manipulation of the variables and therefore it is not possible to establish cause and effect between co-variables

Question 3

What is an example of this?

Answer 3

Even if we found a strong positive correlation between caffeine and anxiety; it may be that people are anxious for many reasons (personality type, stressful job, up-bringing) -the influence of these other variables we cannot assume that caffeine was the cause of anxiety. These other variables are called intervening variables

Question 4

What is a positive correlation?

Answer 4

When one variable increases while the other increases
E.g caffeine and anxiety

Question 5

What is a negative correlation

Answer 5

A relationship between two variables in which one variable increases as the other decreases

Question 6

What are correlational coefficients?

Answer 6

The strength of a correlation is indicated by a correlational coefficient
possibles correlations range from +1 to -1
+1 (perfect positive correlation) meaning that booth variables move in the same direction together
-1 (perfect negative correlation) meaning that as one variable goes up the other goes down