In my opinion the qualities that the inteviewer must have are depending the job that you realise.
1. Appearance. If you have to ocuppy a executive's place you must have a presence, you must dress well, elegant...
2.Qualifications. All of us should have a good qualifications but sometimes is necessary more experience than studies.
3.Work experience. Depends on job and the person. There are people that learn very quickly and they only need one week or less to get a good training.
4.Personality. The personality is a qualitie necessary for all. Each one of us should be ourself.