Interpreting the inventory of interpersonal problems: a rejoinder to Riding and Cartwright

Recently Riding and Cartwright (1999) have advocated eight new subscales of the Inventory of Interpersonal Problems, to be derived from a 40-item short-form (the IIP-40). The aims of this rejoinder are to examine critically the rationale given by Riding and Cartright for constructing new subscales based on Birtchnell's interpersonal octagon, the methods they used for the construction, and the evidence they provided for validity. The conclusions of this examination are that the rationale is weak and that the evidence is against the validity of the IIP-40.