 The potential pool of items is represented by the incidence matrix (Q) matrix of order ("k, p"), where "k" is the number of attributes and "p" is number of potential items.This pool of items represents all combinations of the attributes when the attributes are independent of each other.However, this pool of items can be reduced to form the reduced incidence matrix (Qr), by imposing the constraints of the attribute hierarchy as defined by the R matrix.