the use of a statistical technique that can tell us about the way two variables are related to each other. they may be positively or negatively correlated, or not correlated at all
positive correlation
where as one variable increases so the other one does
negative correlation
where one variable increases at the other one decreases
strengths of correlational evidence
correlation is useful as it allows us to measure the relationship between variable which it would be difficult or unethical to manipulate experimentally
it can be used to test for either reliability or validity as correlation can be found between observations gathered by different observers
disadvantages of correlational evidence
correlation does not mean causation, just because two variables are correlated this does not mean that one of them has caused the other one to change
