Figure 14.18: Using indicator kriging, with the block equidistant from five sample locations, the best indicator estimate (50% probability), determined from the cdf, for the block hydraulic conductivity (K) is 0.12 cm/sec. If ordinary kriging were used, the best estimate would be 2.21 cm/sec. This shows how indicator kriging does not allow high- value outlier data to overwhelm more plentiful low-value data. The cdf may also be used to approximately indicate the probability the block estimate is below a certain value; here the cdf suggests that there is a 75% probability the grade of the block is below 0.24 cm/sec. Use of stochastic simulation would yield a small percentage of realizations with a large K for the block. If enough blocks have the potential to be defined as high K, some realizations will exhibit a continuous zone of high K. The number of realizations which exhibit this condition, divided by the total number of realizations is the probability that such a condition exists.