we generally do defense against 6 basic attacks with a knife. I wouldnt say any of which are 'jab like' in which you attack and recoil very quicly. some can be very fast and feel different to attacks that you are used to defending against, like a knife attack hooking around low on either side to attack the side or the kidney of your opponent.
description not very good :P:P
but I would generally describe our attacks as broad, with very few small and quick movements. But I find that this can be the case with aikido in general in the many places I have trained... armed or unarmed