2012/9/18 Martin Steer <martinsteer@maxi.net.au>
On Tue, Sep 18, 2012 at 04:24:07PM +0200, Benny Malengier wrote:

For bastards the father is sometimes known. But for past relationships it
indeed comes down to following documents, so family is normally clear.

The 'live under same roof' is more about documenting current family constructs.
For example, a family is private or not. Children of a family have no problem
to see them on website or in my family tree in a family with their stepfather,
however, the family with the actual father should be private.

People not being brought up in a single household, surely you have two families
for that.

No. Well, it depends on the documentation. An adopted child has at least
two families.

So what would be the problem of a family with only the mother, and one with
only the father?

Because, given your method ('a family means people under the one roof'),
you're making the implicit claim that they weren't such a family.

Actually, I would say it is explicit as father and mother don't share a family, only birth relation to a child. Hence they cannot share family events with each other.
As you make a single family for this, you need to set relationship to the default Unmarried (which is weak as it can imply many things) or something custom that is more strong (living apart?), which is ok for me, but not how I want to do it. 
In a single family, events become limbo as it is hard to interpret how they can apply to living apart people.


In software, everything can be merged and visualized together anyway.

Not a software problem.