Samenvatting
A modification of Brunswick's lens model is discussed. The modification consists mainly of an attempt to construct, within the lens model, a multidimensional model for the study of the cognitive organisation of the individual. The modified lens model contains four subsystems. These have been designated: input-generating system, perceptual-cognitive system, utilisation system, and instrumental response system. Interactions between these systems are discussed. Research paradigms are presented, which can be used for the study of interactions between the systems.