There are many ways of thinking and writing about history, but the usual practice of scholars with new research to report is to concentrate on subjects sufficiently limited and precise to be thoroughly explored within the limits of a single article or book. This means that such writing is typically detailed and sometimes technical, addressed to fellow-scholars, or at least assuming some knowledge of the subject and its background. It will invariably be supported by a full apparatus of notes indicating the sources, and often by statistics, documents and other evidence. For general readers or undergraduates, historians will adopt a different style, covering a broader sweep of the past by summing-up their own and others' research. Such writing is designed to be more accessible, but it too will be supported by references to the published works on which it is based. Both sorts of history are firmly based on the most and best available evidence. This is fundamentally factual history, of what is known for certain or can be confidently inferred. The conventions intended to ensure intellectual rigour provide it with a formal structure which deliberately limits the scope for speculation. The deeper meaning of the history, its significance for modern society, is likely to be left for other writings, if not other writers.

The scholars who have written for the Océanides project are all authorities on their subjects, but they were not asked to write conventional scholarly articles, to undertake fresh research, nor to summarize all that is known on a particular subject in the style of an encyclopaedia. Their brief was to write interpretative essays exploring the significance of a particular subject and period of history through the lens of a single basic question. In its simplest form, the question was ‘was it the sea which made the difference?’, or ‘what difference did the sea make?’ These are simple questions, even simplistic, but they are meant to force authors and readers to reconsider the broad significance of their subjects in a way which conventional detailed scholarship does not usually do. Though the range of subjects and the styles of treatment vary a good deal, the fact that the same basic question is being put to each gives the whole work a common theme and unity.