Correlations

What is the aim of a correlational analysis?

Correlational analysis aims to discover whether or not there's an association or relationship between two different variables (known as co-variables).

A positive correlation

As one variable increases so does another

A negative correlation

As one variable increases the other decreases

A zero correlation

There is no relationship between the two variables

What to include when asked describe the scattergram shows?

•The strength of the correlation (strong/weak correlation)

•The direction of the correlation (positive/ negative)

•A description of the pattern of each variable for e.g the longer the treatment then lower the depression score

What does -1 mean?

A perfect negative correlation

What does 0 mean?

No correlation

What does 1 mean?

A perfect positive correlation

Strength of using correlation analysis

Correlations can suggest trends that can lead to experiments. This is a strength because if a relationship between the two variables is established then an experiment in the same area can be conducted to further our knowledge of cause and effect.

Limitation of correlation analysis

As correlations can only measure the degree of interrelationship between two variables they cannot establish if one variable causes another (cause and effect). This is the limitation because conclusions drawn from correlations might not be valid.