This book constitutes the refereed proceedings of the 7th International Symposium on Abstraction, Reformulation, and Approximation, SARA 2007, held in Whistler, Canada, in July 2007. The 26 revised full papers presented together with the abstracts of 3 invited papers and 13 research summaries were carefully reviewed and selected for inclusion in the book. All current aspects of abstraction, reformulation, and approximation in the context of human common-sense reasoning, problem solving, and efficiently reasoning in complex domains are addressed. Among the application fields of these techniques are automated reasoning, automatic programming, cognitive modelling, constraint programming, design, diagnosis, machine learning, model-based reasoning, planning, reasoning, scheduling, search, theorem proving, and tutoring.