  An alternative classification of the Pearson family of probability densities
is related to the orthogonality of the corresponding Rodrigues polynomials.
This leads to a subset of the ordinary Pearson system, the Integrated Pearson
Family. Basic properties of this family are discussed and reviewed, and some
new results are presented. A detailed comparison between the integrated Pearson
family and the ordinary Pearson system is presented, including an algorithm
that enables to decide whether a given Pearson density belongs to the
integrated system, or not. Recurrences between the derivatives of the
corresponding orthonormal polynomial systems are also given.
