AV is right in everythig he says.

The doem is designed to BOUNCE and SPREAD the light, it does very little softening on its own. One thing though, they are meant to be used pointed at about a 45 degree angle to keep most of the light going towards the subject. Typically you wouldn't point it directly at the subject, too much light being tossed at the ground. Of course there are always exceptions depending on what you want...