Just to clarify, and I'm not implying Sir George has the wrong end of the stick.....
The categorisation of approaches as Precision/Non-Precision and Pilot-Interpreted/Ground-Interpreted are completely separate. For example:
ILS is a precision pilot-interpreted approach
PAR is a precision ground-interpreted approach
NDB (and the new GPS approaches) is a non-precision pilot-interpreted approach
SRA (and indeed a QGH for all you old-schoolers) is a non-precision ground-interpreted approach
I can also teach all your grandmothers to suck eggs if you'd like......