“…Specifically, the methods simply consider the domain on which the fuzzy data are defined (the interval whose bounds are m − l and m + r, where m is the center and l and r the left and right spreads, respectively) without considering the codomain (the membership function and, thus, the weights associated to the values in the interval). The most common data reduction methods for interval valued data are the Centers-Principal Component Analysis (hereinafter C-PCA) and the Vertices-Principal Component Analysis (hereinafter V-PCA) proposed by Cazes, Chouakria, Diday, and Schektman (1997) (see also Bock & Diday, 2000;Lauro & Palumbo, 2000;Cazes, 2002) and the Midpoint-Midrange Principal Component Analysis (hereinafter MM-PCA) proposed by Palumbo and Lauro (2003). We will consider such methods in more detail in Section 6.…”