Mark DeBellis wrote:
The question that interests me now is whether the implications of an
identification ("Was that SACD or CD?") test need be the same as those
of a discrimination ("Are A and B the same or different?") test. Does
the research show, in particular, that an identification test (the
kind I undertook) is among the kinds of tests that are reliable for
determining whether two sources sound different?

If by "identification test," you mean that you listen to a single
signal and decide whether it is CD or SACD, that is extremely
difficult, because you must remember what both SACD and CD sound like.
(And, as I've said before, our aural memory for such small sonic
differences is far too short to do that.)

Whereas, in a proper same-different test (or an ABX test, which is a
variant), you have both signals available to you at all times, and can
switch immediately between them, which allows you to compare directly.

Unfortunately, most home users cannot do that sort of a test, because
it requires you not only to level-match the two (relatively easy) but
also time-sync them (very hard). It would be too easy to tell that the
two were different if one were running even fractionally ahead of the
other.

bob