This paper explains why the knowledge discovery in database (KDD) procedure models lacks verification and validation (V&V) mechanisms and introduces an approach for integral V&V. Based on a generic model for knowledge discovery, a structure named 'KDD triangle model' is presented. This model has a modular design and can be adapted for other KDD procedure models. This has the benefit of allowing existing projects for improving their quality assurance in knowledge discovery. In this paper, the different phases of the developed triangle model for KDD are discussed. One special focus is on the phase results and related testing mechanisms. This paper also describes possible V&V techniques for the developed integral V&V mechanism to ensure direct applicability of the model.