Although relatively formulaic, this paper is flawless in its simplicity and elegance. After the obligatory introduction examining the importance of sensitivity measures and past techniques for evaluating them, the authors discuss global sensitivity measures and proceed to focus on the correlation ratio. They then discuss the accepted methods for estimating the correlation ratio (such as the Bayesian approach and polynomial approximation methods). However, the authors stress the value of determining the correlation ratio using the early stopping method.

As I said before, the paper is crystal clear in its presentation and elegance. It also contains an extensive reference section. Although certainly not required, I would have liked to see more discussion of the important ethical issues.