From what aspect 'compability'?
As friend, working partner, marriage, girlfriend-boyfriend, as identical twin ....
As for living together it is rather complex to predict the outcome.
Sometimes shared interests are good.
But also sometimes difference in personality is great.
They become complementing eachother. Eventhough being very different.
To the point you ask about:
- measures the comparability by meshing up the two sets of answers
This is perfectly possible. I would say it is easy & suitable for PHP scripting.
Naturally, such a test will not be better than the validity of criterias used
to measure any sort of 'compability'.
A great fun project, it would be. In my opinion
🙂