This description of the content and structure of a 10-year Icelandic Social Science Curriculum Project serves as a commentary on the role of the project in the context of Icelandic curriculum reform. A discussion of the place of structural developmental curricula in the reform dynamics of educational progressivism precede the specifics of the Icelandic reform context. The description of the special features of the project includes its role in the production of concepts, instructional materials, and teacher materials representing the integration of knowledge about man, society, and the ecological conditions of man's life on earth--a representation systematically built from a wide variety of social science disciplines using the inductive processes and discovery approaches as specified by developmental didactics. Next is a discussion of factors contributing to the defeat of the project; a defeat triggered by an onslaught of neo-fundamental ideologies in which perspectivism and socio-moral understanding were defamed as indoctrination and the goal of developmental education was replaced by the "Back to Basics" movement. Experiences gained and motives operating during two decades of Icelandic educational reform are then discussed and reasons for the vulnerability of rational and rationalist reforms are examined. Tables and appendices include (1) an overview of the project's K-9 social studies course; (2) a structural matrix of key concepts; (3) examples of the linkage of key concepts and content in a widening spiral framework; (4) a presentation of a unit; and (5) examples of second and third grade task structures, organization of tasks, and objectives. (LH)