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From: edhall@randvax.ARPA (Ed Hall)
Newsgroups: net.audio
Subject: Re: Results of a subjective speaker wire evaluation
Message-ID: <1691@randvax.ARPA>
Date: Sat, 18-Feb-84 00:20:33 EST
Article-I.D.: randvax.1691
Posted: Sat Feb 18 00:20:33 1984
Date-Received: Wed, 15-Feb-84 06:13:54 EST
References: <824@drufl.UUCP>
Organization: Rand Corp., Santa Monica
Lines: 37

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That's not a double-blind test!  It's hardly even a `single blind' test.

In a double-blind test:
    1) The order in which the cables were listened to would be random.
       This can include listening to the same cable twice in succession.

    2) Neither the person running the test nor the subject would have
       any way (other than by listening) of determining which cable
       was in use.  (This is the double-blind part, and has proven
       important in evaluative studies of all kinds, since unconcious
       cuing (e.g. the `Clever Hans' effect) is a definite posibility.)

    3) The results would be checked for statistical signifigance.  This
       is tough for a small sample.

Admittedly, #2 is a tough order.  It possibly could be done by placing
short, coded wire pigtails on each end of several samples of cable, and
somehow hiding which cable a given pigtail attached to.  Or, cable-
changing could be done behind some sort of screen (not exactly double-
blind, but so long as no one in the listening room knew the sequence
to be used it should suffice).

I'm not denying that there can be a difference made by speaker cables.
But if you claim a study is `double-blind', you'd best know what you
are talking about.

		-Ed Hall
		decvax!randvax!edhall

P.S.  `Clever Hans' was a horse around the turn of the century who
      seemingly could answer all sorts of yes/no and small-number
      questions by stamping his hoof.  It was eventually noticed
      that Hans could only answer questions his owner knew the
      answer to, and then only when the owner was within eyeshot.
      It seems that the horse was cued by his owner's posture and
      breathing.