Figure 2: The sensitivity (a) and the specificity (b) are plotted versus , the number of variables selected for conditioning, for the first example, the rooted tree. The number of samples is 100, and the order is ; similar results are obtained varying . The results are averaged over 100 realizations of the linear dynamical system described in the text. The empty square, in correspondence to , is the result from the bivariate analysis. The horizontal line is the outcome from multivariate analysis, where all variables are used for conditioning.