couple of pages back, Sahil, a forum member, posted a copy of actual interview letter that he had received. Take a look at it. If the sponsor is overseas, they might talk to him/her (note that it is not they will since it is left to the discretion of the visa officers) but should be by the phone in case they want to talk. If the sponsor is in India, then he/she will be asked to come with sponsored person. Sometimes they let both parties sit and answer questions; sometimes it is one after the other to compare notes as to sponsored person said first and then compare it with sponsored person; sometimes it is just sponsored person only...