Resumen
In the knowledge-based economy, developed and in developing countries are putting an increasingly interest on encouraging their firms to produce, exploit, transfer and apply knowledge. In this context, there seems to be a general agreement about the need to develop and strengthen networking activities using infrastructures to promote knowledge transfer between different economic actors. Science and Technology Parks (STPs) are an important part of these support infrastructures. The main objective of this paper is to analyze how STPs have evolved during the last 25 years in Spain. Therefore with available data we study how has changed their model from a "science push" in the first generation models to a "science pull" for the second generation models of Science Parks. Data from the APTE (Spanish Association of Science and Technology Parks) shows that new parks are redesigning their activities toward a third generation of STPs based on interactive local flows located in science-industry-government relations, increasingly involved with local, regional and even global innovation activities. This paper also analyzes how go-betweens and intermediaries can facilitate the interaction between firms, government and research institutions, and liaise with public and private R&D funding and venture capital organizations.