On the other hand, it is difficult for the average designer working under
deadline pressure to keep up with every facet of the industry, because there
is SO MUCH scientific information out there.

I am in complete agreement that one should question "rules of thumb" and
reasons given "because we've always done it this way", because there has to
be something behind it. Without knowing the foundation its hard to know the
importance of it and under what conditions it can be considered a
"trade-off" to a more important guideline or rule when designs get more
complex.
But my feeble brain can't hold too much more, its almost full. When I read a
report I tend to summarize the findings into an easy "rule of thumb" that I
can remember. The problem is that later when the subject comes up again, I
only remember the guideline, not all the facts that supported it, so it is
difficult to prove.

So while I get frustrated when people spew rules at me without knowing why
they are the way they are, I can understand how it happens and at least have
a starting place for where to start looking. (Thanks for responding)

onward thru the fog...
Jack

                -----Original Message-----
                From:   Abd ul-Rahman Lomax [mailto:[log in to unmask]]
                Sent:   Friday, May 07, 1999 9:18 PM
                Subject:        Re: Unconnected inner-layer pads

                I've noticed for years that there is a paucity of truly
scientific
                information regarding many areas of P.C. Design. Many items
of "common
                wisdom" are really someone's bright idea that might be true
and might not
                be true. In genuine science, theory takes a back seat to
actual experiment,
                and a scientific report would never say that something
"should" always be
                done. Rather it would simply report how varying one item
under specified
                conditions affected subsequent experience or measurement.



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