"Malcolm" wrote in message
...

No pre-judging involved whatsoever. I have not "asserted" that A and B
are necessarily different. The same conclusion (quoted above) applies
whether A and B are different ot not. All I'm saying is that if such
a test fails to show a difference between A and B then that at the end
of the test you still have no "certainty" whether A is different to B
or not.


Certainty is a rare thing in this world. Even if a test apparently shows a
difference there is no certainty that there is one, as people quite commonly
vote A better than A when they aren't aware that they are hearing exactly
the same thing twice.

David.