Definition of correlation
Measuring relationships between two variables.
The relationship between the variables is increasing which means the correlation is close to +1.
The relationship of the variables is decreasing which means the correlation is close to -1.
There is no relationship between the variables.
Represents what the data is comparing.
Analyses how significant the correlation is to, for example +1 would be a perfect positive correlation and -1 would be a perfect negative correlation.
Can be used when it would be unethical or unpractical to conduct an experiment. This will avoid ethical issues.
If correlation is significant then further investigation can be justified. This increases the validity of investigations.
People misinterpret and assume that a cause and effect have been found whereas this is not possible. This can be overcome by training researchers to analyse the relationship between the co-variables carefully.
Extraneous variables can lead to false conclusions causing low inter-rater reliability. This can be overcome by training researchers to identify the extraneous variables.
Link to study
Maguire studied parts of the brain of non taxi drivers and parts of the brain of London taxi drivers. He proved that the size of London taxi drivers hippocampus had grown because taxi drivers had studied the knowledge.