Table 1 Statistical approaches for interdependence analysis of immunological markers dependent on the scale of measurement
Scale of measurement | Bivariate methods | Multivariate methods |
|---|---|---|
Binomial (e.g. positive, negative) | Contingency table; tests: Chi-square or Fisher’s exact test; association measure: phi coefficient, Yule’s Q | Multilayer contingency table, classification trees |
Nominal (e.g. Th1, Th2, or T-Reg) | Contingency table; tests: chi-square or Fisher’s exact test; association measure: contingency coefficient | Multilayer contingency tables, correspondence analysis, classification trees |
Ordinal (e.g. low, medium, high) | Contingency table; tests: chi-square or Fisher’s exact test, tau test; association measure: Spearman-Rank correlation, Kendall’s Tau or Goodman and Kruskal’s γ | Multilayer contingency tables, correspondence analysis, classification trees |
Continuous (non-normal distributed) | Scatter Plots; test: Spearman-Rank Correlation, criteria: Kendall’s Tau or Goodman and Kruskal’s γ | Factor analytic techniques: e.g. principal component analysis |
Continuous (normal distributed) | Scatter Plots; test and association measure: Pearson correlation coefficient | Factor analytic techniques: e.g. principal component analysis |