Question

How would you interpret a correlation coefficient of -0.95 between the two parameters; age of the patient and the testosterone level? How would your interpretation change if the coefficient was 0.03 or 0.48?

Answer 1

By Correlation we mean the association or interdependence between two variables. Correlation coefficient ranges from -1 to +1. If one variable increases as the other increase the variables are said to be positively correlated. Again, if one variable decreases as the other increases then there are negative correlation. There is also a third case where correlation is zero or the variables are uncorrelated.

Here, correlation coefficient between the two parameters; age of the patient and the testosterone level is -0.95. This means that there is a perfect/high negative correlation between the parameters i.e if age of patient increases the testosterone level decreases and the vice versa.

If the correlation between the parameters is 0.03, then it means that there is almost no correlation or very low positive correlation. We can tell that if one parameter increases then the other remains constant on average.

If the correlation between the parameters changes to 0.48 then there is moderately positive correlation between the parameters. If one of the parameter increases then the other is also observed to be increases.

The scatter diagram showing correlation between two variables -

I hope you have no further doubt regarding interpretation of correlation.