Correlation Simple correlation; Measurement of a correlation; Correlation coefficients (Pearson product-moment, Spearman’s rho); Significance and correlation coefficients;Variance estimates; SPSS procedures for correlation;What you can’t assume with a correlation; Categorical variables; Common uses of correlation in psychology; Regression and multiple regression; Multiple predictions; Partial and semi-partial correlation; Regression coefficients; Effect size and power; Conducting a regression analysis in SPSS

ABSTRACT

Correlation is the measurement of the extent to which pairs of related values on two variables tend to change together or ‘co-vary’; it is a standardised measure of co-variation. If one variable tends to increase with the other, the correlation is positive. If the relationship is inverse, it is a negative correlation. A lack of relationship is signified by a value close to zero but a value of zero could occur for a curvilinear relationship. These relationships can be illustrated in a scatterplot.