We consider the accuracy estimation of a classifier constructed on a given training sample. The naive resubstitution estimate is known to have a downward bias problem. The traditional approach to tackling this bias problem is cross-validation. The bootstrap is another way to bring down the high...

One hundred years ago Karl Pearson derived an approximate formula for the correlation between ratios with a common divisor and cautioned to be wary of correlating ratios. The exact formula for the correlation between ratios is derived. It can provide a better reference point of no connection...