ABSTRACT
Having gone through the book chapters, the reader has hopefully gained a good appreciation of the reasons that have led to semantic-aware interoperability approaches and ontology integration in the geospatial domain. This appreciation is subsequently supported by a balanced mixture of: (a) theoretical principles, (b) structures and tools, and (c) practical approaches to ontology integration, enriched with guidelines and examples. This chapter starts with a retrospective (and naturally more knowledgeable) view of the main issues addressed in the book and their effectiveness. It then proceeds with some areas requiring extensive research.
