Ainoa Marzabal is a Science Education professor in the Pontificia Universidad Católica de Chile (Chile). She has a PhD in Science Education, received from the Universitat Autónoma de Barcelona. Her current line of research is modelling-based school science education, considering both teaching and learning, as well as science teacher education. She has published several book chapters and papers about that subjects, both in Spanish and English. Her concern is mainly about how to address the science school curriculum, overloaded and fragmented, through the identification of its structuring nuclei, understood as school science models. Her current research focuses on identifying the learning progression of school chemical models, contributing to the understanding of the learning processes through which the multimodal representations of students are transformed by modelling processes in the science class. Cristian Merino is a Science Education professor in the PontificiaUniversidad Católica de Valparaíso (Chile). He has a PhD in Science Education, received from the Universitat Autónoma de Barcelona. His research interests focus on the characterization of chemical school activity for the development and analysis of innovation activities that favor the construction of school scientific explanations, with emphasis on the transit between the phenomenon and the theory under a modelling approach through experimental activities through technological and cognitive mediations, for the training of science teachers (especially in chemistry).