Let's say your character enters the apartment of a known criminal who was brutally murdered and wants to look for clues. We will divide up the information the PC should get into "tiers" for ease of explanation.
Tier 1: The things the PC sees just because the PC has eyes. This will include questions and answers for clarification. No roll is needed and positioning aside from "in the room" doesn't really matter.
Tier 2: The "hidden" information that requires an active search. Maybe "hidden" means subtle, maybe it means small, maybe it means obscured and maybe it means actually intentionally concealed. In any case, it requires a Perception roll, and positioning matters to some degree. For example, as GM I would probe to find out if the PC is rifling through papers, opening drawers etc... This might impact the difficulty as well as be important for a role playing scene later when the Inquisitor confronts them for disturbing the scene before the officials could get there. or whatever.
Tier 3: The process of connecting the visual clues and other uses of the Investigation skill. Positioning hee is similar to Perception for similar reasons.
Some players will be very specific -- sometimes too specific -- in their descriptions of where they look, and some players will be vague and may need some prodding. Since I agree that the player does not need to have the same skills as the character to be effective, I wouldn't force them to describe every action, but I would want to get a sense of positioning and general process (hence the probing questions).