Comparison of the probability P_2D relative to P_3D in the case of the member sample of each MG. On the lower left box of each panel, the solid red, long-dashed blue, dotted orange, and dash-dotted green lines delimit the areas of sources whose classifications from our two methods are in full agreement, possible agreement, possible disagreement, and complete disagreement, respectively. This corresponds to the membership categories “G”, “P”, “U”, and “N” (Table 2). The membership thresholds of both procedures (vertical and horizontal lines) and the one-to-one relation (dashed gray line) are shown as well. In each of the five panels, we plot the histograms of the probabilities P_3D(top box) and P_2D(right box) with a bin size of 2% using the same color code.