"A little stress" can be defined a number of ways..

Are we talking "shear stress" on a joint
or "sag stress" from a bookcase ?

There are big differences between a chair and a table.
Both get stress but you can guess which one receives the
very most.

What are you building will be required to give a real
answer.

wrote:

The project I'm working on requires a butt joint that will undergo a little
stress. I'm obviously going the glue the length of the joint, but I'd like
to reinforce it with a)screws, b)dowels, or c)biscuits. Anyone have an
opinion as to which of these 3 would add the most strength to the joint?