Positions available on an Intrepid-class' bridge include Captain, First Officer, Ops, Tactical, Auxiliary Tactical (right behind the captain, aka "Seven's place"), Science, Engineering and Flight Control. You can fill all the positions or not. They never really showed the Engineering and Science positions, and Auxiliary Tactical wasn't even there (IIRC) until Seven came on board and they needed a reason for her to be on the bridge (or, if it was, it wasn't used until then).
Former Decipher RPG Net Rep
"Doug, at the keyboard, his fingers bleeding" (with thanks to Moriarti)
In D&D3E, Abyssal is not the language of evil vacuum cleaners.