This chapter gives a short overview of the basic concepts of probabilistic and deterministic
models, regression, regression lines, residuals, coefficient of determination, residuals and standard deviation of regression. Correlation and Spearman rank correlation are also under study. Two multivariate
techniques, multiple regression and principal component analysis are also discussed. The procedures for
the computations are given in SPSS
Keywords: Regression, Inverse regression, Correlation, Rank correlation.