[sci.electronics] Double-blind tests

max@eros.uucp (Max Hauser) (09/15/87)

In article <3837@watdcsu.waterloo.edu> bmaraldo@watdcsu.waterloo.edu (Commander Brett Maraldo) writes:

>  I agree that double-blind testing is a method of discovering
>  differences, or lack there-of, in two or more different audio
>  systems.  This can also be said for any method of system evaluation,
>  the question is which method provides the most accurate results... But
>  is double-blind testing the definitive test method?  This is certainly
>  and arguable point, as it is as objective as the golden-ear phenomenon.
>  ...
>  I do not feel that a simple double-blind test can report more accurate
>  data than an extended listening test...

This beggars reason. As Paul Fussell wrote in a different context, it
would "seem to argue a total breakdown in public secondary education."
Double-blind simply means, of course, that you do not know what is
really going on, so you cannot cheat. That option can be added to any
kind of experiment, including "extended listening tests." It does not
require the presence of "a large number of people," let alone "at least
one member of a group of potentially biased individuals" (indeed the
whole point of DOUBLE-blind, as opposed to simply blind, tests is to
avoid influence from persons, if any, other than the subject).
It does not require any specific set of "listening environments."
All double-blind testing really requires is honesty and sincerity.

>  What I do take seriously are what my ears hear.  If I hear a 
>  difference between signal cable, you can not argue that I do 
>  not hear that difference.  

Of course. Far from contradicting, double-blind testing 
(generically defined) indeed facilitates your determining whether
you do hear a difference, stripped of beguiling influences like
the five thousand you spent on one set of cables, or the fact that
those speakers "aren't just speakers, they're Mistmeisters!"

On the other hand, if you are saying that you want to enjoy your
speaker (or cable), knowing that you paid $XXXX for them and that
they are Name Items, that is perfectly legitimate and I would
defend that right to the limit of my ability. Just don't claim that
you can hear a difference without being prepared to back it up.

Max W. Hauser, UC Berkeley

   UUCP: ...{!decvax}!ucbvax!eros!max
   Internet (old style): max%eros@berkeley
   Internet (domain style): max@eros.berkeley.edu

bmaraldo@watdcsu.UUCP (09/16/87)

In article <1858@ucbcad.berkeley.edu> max@eros.UUCP (Max Hauser) writes:

> All double-blind testing really requires is honesty and sincerity.

    Then you say...

> Just don't claim that you can hear a difference without being prepared
> to back it up.

    In order to present the results of a subjective analysis, it is
    important to prepare the analytic procedure such that you can convince
    any number of people that you have proceeded in a scientific method.
    The double-blind test is a scientific method; honesty and sincerity do
    not enter the picture.  Example:  'I performed a double-blind test in
    which I ABXed two speaker systems.  I identified speaker A 15/16
    trials.' - this is a typical example of the verbiage used to document
    many such 'double-blind' test procedures.  It is honest and scincer,
    but it lacks description of scientific method.  This is the format many
    documented double-blind testare found in.  It is inadequate as it shows
    no evidence of scientific methods or procedures; only objectivism and 
    naivete to scientific method.

    I assume that honesty and sincerity are inherent in a test report.  I
    expect process and implementation to be explained in detail; only then
    can I take a report seriously.

					Brett L Maraldo


    prepare the 

-- 
               --------     Unit 36 Research     ---------
	                "Alien Technology Today"
               -------------------------------------------
	                    bmaraldo@watdcsu

sjc@mips.UUCP (Steve "The" Correll) (09/19/87)

In article <3849@watdcsu.waterloo.edu>, bmaraldo@watdcsu.waterloo.edu (Commander Brett Maraldo) writes:
>     ...it is
>     important to prepare the analytic procedure such that you can convince
>     any number of people that you have proceeded in a scientific method.
>     ...Example:  'I performed a double-blind test in
>     which I ABXed two speaker systems.  I identified speaker A 15/16
>     trials.' - this is a typical example of the verbiage used to document
>     many such 'double-blind' test procedures.  It is honest and scincer,
>     but it lacks description of scientific method.  This is the format many
>     documented double-blind testare found in.  It is inadequate as it shows
>     no evidence of scientific methods or procedures; only objectivism and 
>     naivete to scientific method.

Are you familiar with the double-blind amplifier comparison described
in the January 1987 "Stereo Review"? The article documents the size and
shape of the listening room, the number of listeners (both pro- and
anti-golden ear), the music used (listeners were allowed to bring their
own, which turned out to include material on both LP and CD from
Reference Recordings and Sheffield), the equipment and cables used
(aside from the amplifiers under test, it was chosen by the proprietor
of a Wisconsin high-end shop), the method of switching (listeners could
use an ABX box or, if they preferred, they could have the speaker
cables swapped by hand after extended listening), the number of trials,
the duration of the listening sessions. The article is really pretty explicit
about the test procedures.

The result? I won't give away the ending, except to say that the next system
I buy may be made in Japan :-).
-- 
...decwrl!mips!sjc						Steve Correll

wtm@neoucom.UUCP (09/20/87)

Double blind tests; that's what happens when a golden ear, enrgaed
by transistor harshness, veiled high end and flabby bass... pokes
out the left and right eyes of the researcher. Correct?

Bill
(Bill Mayhew  wtm@neoucom.UUCP)