Correlation
Correlation is a statistical relationship between variables.
The illustration below shows various correlations between variables x and y:
Correlation Coefficient
The correlation coefficient is often measured using the Pearson Product-Moment Correlation Coefficient (PPMCC), or simply the ‘correlation coefficient’.
The correlation coefficient ranges between +1 for completely positive correlations and -1 for completely negative correlations.
Statistical Population Correlation
A statistical population is a set of similar items or observations under study. For more formula details see:
Statistical Sample Correlation
A statistical sample is a set of items or observations selected from a statistical population.
Coefficient of Determination
The coefficient of determination, or "r squared", is the proportion of the variance in the dependent variable that is predictable from the independent variable(s).
The coefficient of determination ranges between 0 for no correlation and +1 for complete correlation.