Comment on “Indicator principal component kriging” by V. Suro-Pérez and A. G. Journel

Conclusions The indicators covariance is equivalent to the bivariate distribution of the class index. The factor decomposition of the indicator covariance proposed by SPJ is an isofactorial model of the corresponding bivariate distribution. However, the choices of cumulative indicators and of principal component analysis produce unacceptable inconsistencies. In LL, a correspondence analysis of the bivariate distribution was used to produce more satisfactory empirical factors. These were used in the procedure of identification of discrete isofactorial models, with improved consistency, and the benefit of change of support models.