On Sat, 24 Feb 2001, Donald Burrill wrote:
> On Sat, 24 Feb 2001, Mike Granaas wrote:
>
> > Interesting point. Yes, if the Ss do something other than a random guess
> > the binomial model would be violated. The question then becomes what
> > would they do if they are uncertain? I suspect that they would fall back
> > on visual inspection...which piece appears to be different than the others
> > (less green pepper, more browned, etc) Such information is probably
> > relevant often enough that "guessing" would be well above 1/3.
>
> So what you would then have is evidence that Ss can in fact do better
> than "chance", but you might NOT know whether that improvement is due to
> their actually being able to perform as claimed, or to some other
> factor(s) relevant to identifying the "odd pizza out": a human-cum-pizza
> version of "Clever Hans", pehaps?
Yes.
>
> > Using blindfolded Ss will deal with that problem, and gets us back to
> > the question that Dennis is asking. I'm guessing that rather than going
> > through some sort of a systematic process (e.g. binary decision for the
> > first piece, progress to second piece only if first piece was judged
> > "same".....)
> Umm: Logical problems here.
> (1) How can _first_ piece be judged "same"? Same as what?
> (2) Why would Ss not taste all three pizzas, given the ground rules
> Dennis specified (or implied) at the outset?
Yes, the Ss would taste all three pieces of pizza, possibly multiple
times, before arriving at their judgement. Here "first" refers to the
order in which a particular set of three slices was presented to S. Later
I refer to them as slices "A", "B", and "C".
As I understand Dennis' earlier comment, S, after tasting these three
slices to their hearts content, would, if uncertain, tackle the decision
making process by starting with the first of the three slices presented.
That is they would start by making a binary decision about "A" and only
move on to considering "B" if they decide that "A" is not the odd slice.
>
> > ... Ss will in fact do something more like guessing. Only they
> > will condition their guesses such that if they picked slice A as different
> > on the previous trial they will first consider slices B and C on the
> > current trial (they will actually avoid selecting the same slice position
> > on sequential trials).
> How did "sequential trials" get into the
> scenario? As I read Dennis' description, each S was to taste the three
> pizzas presented (perhaps tasting each more than once, but not attacking
> a whole 'nother SET of pizzas).
My reading was that there would be 10 trials per subject. If each S
participates in one, and only one trial, then this speculation is outside
of the problem bounds.
>
> > Furthermore they will try to equalize the number
> > of position choices they make across the experiment so that they choose
> > each of A, B, and C three times and one of those a fourth time.
>
> This sounds as though you thought each S were going to have ten separate
> trials at identifying the "odd pizza out", with a different set of three
> pizzas each time. I don't see how else "choosing each of A, B, and C
> three times and one of those a fourth time" could mean anything else;
> but if I've misunderstood, doubtless your reply will explain.
> However interesting such an experiment might be, it's not the experiment
> that I thought Dennis described.
Yes, I read the original post as suggesting that there would be 10
replications of the taste test for each S. I'll have to go back and read
Dennis' original question again.
Michael
>
> < snip, the rest >
> -- Don.
> ----------------------------------------------------------------------
> Donald F. Burrill [EMAIL PROTECTED]
> 348 Hyde Hall, Plymouth State College, [EMAIL PROTECTED]
> MSC #29, Plymouth, NH 03264 (603) 535-2597
> Department of Mathematics, Boston University [EMAIL PROTECTED]
> 111 Cummington Street, room 261, Boston, MA 02215 (617) 353-5288
> 184 Nashua Road, Bedford, NH 03110 (603) 471-7128
>
>
*******************************************************************
Michael M. Granaas
Associate Professor [EMAIL PROTECTED]
Department of Psychology
University of South Dakota Phone: (605) 677-5295
Vermillion, SD 57069 FAX: (605) 677-6604
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All views expressed are those of the author and do not necessarily
reflect those of the University of South Dakota, or the South
Dakota Board of Regents.
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