Fig. 1From: Joint use of over- and under-sampling techniques and cross-validation for the development and assessment of prediction modelsCombination of sampling and CV methods used in the simulations and real data analyses. CV includes Sampling (first row) constitutes the correct approach, while Sampling followed by CV (second row) is the incorrect approach. The samples included in the original dataset are indicated using upper cases, while their copies are indicated with lower casesBack to article page