I think your approach to this question derives from the principles of your
overiding teaching/learning philosophy.
A principle paramount in my appraoach is "Tell them how you know!". I
think Aarons emphasized this in almost those very words.
If you are teaching religious catechumens, the (often wrongly) stereotyped
engineering major, or a wannabee pilot/car driver who simply wants to know
how to drive, this may not be the most efficient course - they will
perhaps prefer things pulled out of the air. My penchant stems from an
inborn skepticism fed by much nonsense taught by many teachers in many
subjects.
The application of this principle must of course be adjusted to the level
and requirements of the audience, but I personally could not teach at any
level without at least trying to instill a skepticism which will question
(at least for future action) everything I say and insist: "Prove it!"
(whatever that may mean at their level).
Ciao! (pronounced "chow", to re-awaken a distant thread!)