Pearson r coefficient varies between –1 and +1, with +1 indicating a perfect positive relationship (a high score on variable X = a high score on variable Y), -1 a perfect negative relationship (a high score on X = a low score on Y), and 0 no relationship. Thus, in our example a correlation coefficient close to +1 would mean that if we scored high in English, we are likely to score high in maths as well. A coefficient close to -1 would suggest that if we scored high in English, we would score low in maths, while a coefficient close to 0 would suggest that getting good grades in English were not associated with grades in maths at all (i.e. the two are unrelated).
Thus, Pearson’s r gives us information about a number of aspects of the relationship: