Coefficients of Alienation and Determination

The coefficient of correlation evaluates the similarity of two sets of scores obtained from two variables (or one variable measured twice) within a single sample. It indicates the amount of information common to the two variables. Because this coefficient takes values between −1 and +1, it is difficult to interpret or describe its quantitative meaning easily. For example, it is tempting to interpret a positive correlation as a proportion because it is a decimal number between 0 and 1 and looks like a proportion, but that would not be correct. We can square a correlation, however, and that does create a proportion. A squared correlation is called the coefficient of determination and gives the proportion of common variance between the two variables. Subtracting the coefficient ...