The purpose of this symposium is to bring together recent work on the role of analogies and models in conceptual restructuring from cognitive scientists representing different disciplines and examining similar phenomena from diverse perspectives. Theodore Arabatzis and Despina Ioannidou approach the topic from a philosophy and history of science perspective. Their contribution focuses on the analysis of the ways in which the planetary model mediated the conceptual transformation of J. J. Thomsons plum-pudding model of the atom and transformed the concept of the electron. Cognitive analyses of conceptual changes in the history of science are rare but particularly important from a cognitive science point of view because they provide an opportunity to understand very complex kinds of conceptual processes over long periods of time that are difficult if not impossible to study in the laboratory. Nancy Nersessian is using cognitive-historical ethnographic methods to study how engineering scientists create in vitro models of the phenomena they want to study and manipulate them in order to understand them. As she explains, engineering science is fundamentally analogical practice since simulation models are analogue representations of the entities and processes under study. Stella Vosniadou and Irini Skopeliti approach the topic from a cognitive developmental point of view. They are interested in finding out whether elementary school children can understand analogies and models and can use them to restructure existing knowledge in the process of learning science. John Clement approaches the topic mostly from a science education point of view. He has studied the role of models and analogies in promoting the understanding of science concepts for a very long period of time and has developed an integrating framework that identifies several roles for analogies and explicates the kinds of conceptual changes they promote. The moderator of this symposium is Dedre Gentner who is internationally known for her pioneering work on analogy.