Is this a "conditioned" space or is it open to the whims of mother nature?
Also are there plumbing and ducts in there?
The normal rule of thumb is to insulate the building envelop that surrounds the living space, while allowing the space outside this envelope ( though still part of the home to breath like an attic). In the case of crawl spaces the idea is to seal them up in dry state...this reduces the chance of having condensate from on cool surfaces from humidity influx.
Great question KMS. Need to know a bit more about the crawl space. Current methods bring the crawl space into the living area, much like a basement. If you have heat of any sort the walls down to the floor should be insulated with foam. This will stop drafts up into the room above and remove the need to ventilate or insulate between the floor joists above.
So tell us a bit more about crawl space.
How do you access it? Is there heat running through it to up to the finished room above? How much height do you have from floor to ceiling? And what kind of floor do you have, cement, dirt, something else?