"jim rosinski" wrote\ Here's what Jeppeson's
Instrument and Commercial textbook (2003 edition)
has to say on the subject (page 2-20 on Altimeter Setting):

"The most common altimeter error is also the easiest to correct. It
occurs when you fail to keep the altimeter set to the local altimeter
setting.

That's pilot error. Altimeters have accuracy errors quite independent of
that. Temperature errors are discussed in every level of ground school
training.

moo