So there may be a range of ideas about what the project might produce (if it produces anything), one aspect of which is how the information about a person should be kept and presented. Sam recently wrote:

---- On Thu, 07 Sep 2017 17:46:43 -0700 Sam Wilson <sam@samwilson.id.au> wrote ----

I'm not sure I agree that genealogical research is *uniquely*
structured. It's no more sturctured than, say, writing histories of
companies, or political parties, or railways... I mean that there are
always requirements for strucutred data in any research, but that we
don't bother with bespoke tools for most of them. I think primarily
because the ultimate desired output is readable, linear prose, with
images, figures etc. — I think this is my usual goal with genealogy too.

I view the aim to be something more structured than a collection of pages of unstructured prose, as might be appropriate for histories of railways or Pokemon characters, or for an encyclopedia. It certainly would be nice to have a biography of an ancestor in well-written prose, with photos and maybe circles and arrows and graphs. I do see a need to allow for free form prose and graphics about people so that such biographies can be constructed and preserved.

However the bulk of family history and genealogy doesn't, and often can't, get to that level of knowledge and detail. As we go back in time, less and less information is available. Genealogists are used to dealing with this, and have been using structured data and tools to support the research and analysis since long before computers.

That's why I think the project should produce a system that at its core has structured data, but allows supplementation with free prose where that can be supplied. At the core, every person has a mother and a father, and very often has other relationships such as siblings and children. Every person was born somewhere on some day and died (or will die) somewhere and some time. These are things that are key to researching, establishing, and convincing one another that particular people are related,

The project can serve varying needs, but a major need is to serve as a repository and presentation of the relationship data and the reasons those presented relationships are correct. With hardly any conflict, it can also support producing and reading biographies.

Genealogists need to have the core data about their subjects, and since computers arrived they mostly have been transferring that core data about in some form of file, which is most always some dialect of GEDCOM. The widespread use of it, inadequate as it is in some ways, is highly useful to genealogists. Thus import and export in that format is needed, and structuring of the core person data in the contents of the system itself needs to be fundamental in the approach.