Little is yet known about the reason(s) for the apparently poor product innovation performance of Irish companies. The findings of a small preliminary study carried out in the context of the present research (prompted by the discovery and re-interpretation of an under-exploited finding of an isolated and under-publicized study conducted a decade ago by O’Sullivan and Tomlin (1985)), suggested the significance of the manner in which the product innovation process is managed - but, perhaps more importantly, that ineffective management of the product innovation process may stem from ‘faulty thinking’ about product innovation and an inadequate understanding of the product realization process. A case was thus made for addressing the product innovation performance of indigenous Irish industry primarily in terms of ‘product realization performance’, for investigating the matter, initially, at least, at an organizational level, for using routine organizational product innovation practice as a focal point for the study and for adopting an overall managerial cognition perspective on the problem, the suggested way forward being the further exploration of the nature and effects of managers' beliefs and understanding of how the process of transforming product innovation ideas into marketable products might best be achieved. A model of cognition, practice and performance was proposed and tested using Irish-owned electronics firms as test case. The cognitive component of the model was based on a ‘top-down, knowledge-how, modified script concept using four core product realization activities and sixty-four principles of effective product innovation practice recommended by the international innovation literature as an a priority defined investigative agenda, a Bougon-grid based data elicitation framework and an analytical framework based on the work of Galambos el al and Langfield-Smith and Wirth. The test of the model generated a considerable number of statistically significant and other interesting findings. A number of conclusions were drawn and discussed.