Equidistant Pain Scores with Normality

Context: Need is felt for meaningful computation of statistics of self-reported scales for measurement of pain and to ensure satisfaction of assumptions of techniques like linear regression, ANOVA, Factor Analysis(FA), Principal Component Analysis (PCA), t-test, Cronbach alpha, etc. Aims: To describe methods of transforming ordinal pain scores to continuous equidistant scores to overcome limitations associated with multi-item scales for pain measurement and enabling parametric analysis without violation of assumptions. Method: A non-parametric multi-staged method is described to transform ordinal raw scores