A pilot interpretated approach??? Which bit? A procedural approach means that the pilot may follow a Star and even follow a procedure to self position onto a landing aid ie ILS, VOR, NDB or even GPS.
This is rather than being picked up by radar and given headings to fly as far as PAR or SRA are concerned these can almost be seen as a continuation of the radar facility. In the case of a PAR then yes the aircraft is given directions to remain on the centreline and correct glideslope.
Approaches that are not pilot interpreted are SRA and PRA for example.
With a SRA this is technically still a pilot interpretated approach as while the aircraft maybe directed on the centreline it is still up to the pilot to be at the correct hights and to control his glidepath.
Pace