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I am marking some 50-question, 4-choice, multiple choice tests. (About
20 of them.) The scores are noticeably low, 50%, 64%, 38%, 44%, 52%,...
I begin to worry that the marking key I am using may be mismatched with
the version of the test I am marking. After about nine papers marked,
just as I am about to review the key against the actual questions,...I
get a score of 84%. I am immediately and intuitively certain the key is
the correct one and that this test group is just unusually low
scoring. Is there any science that discusses this sort of phenomena?
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From: Captain Jack
Subject: Re: can this be treated as a probability question?
Date: 12 Feb 2010 16:44:55
Message: <4b75cbd7@news.povray.org>
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"Jim Charter" <jrc### [at] msn com> wrote in message
news:4b75c3e5$1@news.povray.org...
>I am marking some 50-question, 4-choice, multiple choice tests. (About 20
>of them.) The scores are noticeably low, 50%, 64%, 38%, 44%, 52%,...
> I begin to worry that the marking key I am using may be mismatched with
> the version of the test I am marking. After about nine papers marked,
> just as I am about to review the key against the actual questions,...I get
> a score of 84%. I am immediately and intuitively certain the key is the
> correct one and that this test group is just unusually low scoring. Is
> there any science that discusses this sort of phenomena?
I don't know, but I'm pretty sure that process is the foundation of all
modern organized religion.
--
Jack
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From: Jim Charter
Subject: Re: can this be treated as a probability question?
Date: 12 Feb 2010 17:02:41
Message: <4b75d001$1@news.povray.org>
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Captain Jack wrote:
> "Jim Charter" <jrc### [at] msn com> wrote in message
> news:4b75c3e5$1@news.povray.org...
>> I am marking some 50-question, 4-choice, multiple choice tests. (About 20
>> of them.) The scores are noticeably low, 50%, 64%, 38%, 44%, 52%,...
>> I begin to worry that the marking key I am using may be mismatched with
>> the version of the test I am marking. After about nine papers marked,
>> just as I am about to review the key against the actual questions,...I get
>> a score of 84%. I am immediately and intuitively certain the key is the
>> correct one and that this test group is just unusually low scoring. Is
>> there any science that discusses this sort of phenomena?
>
> I don't know, but I'm pretty sure that process is the foundation of all
> modern organized religion.
>
> --
> Jack
>
>
LOL I understand you. That certainty that the appearance of
intelligence cannot possibly be a random result.
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> I am marking some 50-question, 4-choice, multiple choice tests. (About
> 20 of them.) The scores are noticeably low, 50%, 64%, 38%, 44%, 52%,...
> I begin to worry that the marking key I am using may be mismatched with
> the version of the test I am marking. After about nine papers marked,
> just as I am about to review the key against the actual questions,...I
> get a score of 84%. I am immediately and intuitively certain the key is
> the correct one and that this test group is just unusually low
> scoring. Is there any science that discusses this sort of phenomena?
Maybe the one who got 84% was cheating using the same key as you had :-)
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From: Jim Charter
Subject: Re: can this be treated as a probability question?
Date: 22 Feb 2010 22:46:15
Message: <4b834f87$1@news.povray.org>
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scott wrote:
>> I am marking some 50-question, 4-choice, multiple choice tests. (About
>> 20 of them.) The scores are noticeably low, 50%, 64%, 38%, 44%, 52%,...
>> I begin to worry that the marking key I am using may be mismatched
>> with the version of the test I am marking. After about nine papers
>> marked, just as I am about to review the key against the actual
>> questions,...I get a score of 84%. I am immediately and intuitively
>> certain the key is the correct one and that this test group is just
>> unusually low scoring. Is there any science that discusses this sort
>> of phenomena?
>
> Maybe the one who got 84% was cheating using the same key as you had :-)
>
Good point.
I think another explanation is that the key was correct but some static
set of answers were incorrect so that all the marks were depressed by a
constant amount.
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From: Phil Cook v2
Subject: Re: can this be treated as a probability question?
Date: 4 Mar 2010 05:56:37
Message: <op.u81h0wchmn4jds@phils>
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And lo On Fri, 12 Feb 2010 21:11:07 -0000, Jim Charter <jrc### [at] msn com>
did spake thusly:
> I am marking some 50-question, 4-choice, multiple choice tests. (About
> 20 of them.) The scores are noticeably low, 50%, 64%, 38%, 44%, 52%,...
> I begin to worry that the marking key I am using may be mismatched with
> the version of the test I am marking. After about nine papers marked,
> just as I am about to review the key against the actual questions,...I
> get a score of 84%. I am immediately and intuitively certain the key is
> the correct one and that this test group is just unusually low
> scoring. Is there any science that discusses this sort of phenomena?
Okay think what a number of students/result graph would look like if there
were no questions, just random ticks of the box. You'd expect a peak
around the 25% mark tapering off on either side.
Now if there are questions and the people taking the exam are expected to
know the answers you'd expect the peak to move to the right. Just like
asking a mathematics class -
What is 1+1?
a)1
b)2
c)3
d)4
And similar easy questions.
Now imagine a misprint so the question reads - What is 1*1? What would you
expect to happen to the graph with the same class? The peak would move to
the left. This would also be the equivalent of having the wrong answer
grid.
So taking the results you've given I'm just guessing you've got a
low-scoring class; or the 'wrong' answer grid you're using is very similar
to the 'correct' one.
--
Phil Cook
--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com
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Phil Cook v2 wrote:
Welcome back, Phil *V2*
Where have you been?
--
Best Regards,
Stephen
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From: Phil Cook v2
Subject: Re: can this be treated as a probability question?
Date: 5 Mar 2010 04:17:02
Message: <op.u8272yq7mn4jds@phils>
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And lo On Thu, 04 Mar 2010 20:55:00 -0000, Stephen <mca### [at] aoldot com>
did spake thusly:
> Phil Cook v2 wrote:
>
> Welcome back, Phil *V2*
> Where have you been?
Here and there. Got into the habit of using Firefox to write my blog when
I use Opera to track this group; pretty much raised my head one day and
thought "Hey has it really been that long since I've checked in?"
And "oh look a probability question, yummy"
I've also just remembered the other problem, Opera's stopped tracking
threads automatically.. Might take a look at Thunderbird see if that's any
better.
--
Phil Cook
--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com
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From: Jim Charter
Subject: Re: can this be treated as a probability question?
Date: 16 Mar 2010 22:33:01
Message: <4ba03f5d@news.povray.org>
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Phil Cook v2 wrote:
> So taking the results you've given I'm just guessing you've got a
> low-scoring class; or the 'wrong' answer grid you're using is very
> similar to the 'correct' one.
>
Yes, a small, fixed number of wrong answers on the marking key would
give the same result I suspect also. But it is interesting to me how
intuitively we discount the possibility that the one high score is a
random outcome, but rather the proof that the key is okay, or mostly
okay, and the class is low scoring.
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From: Phil Cook v2
Subject: Re: can this be treated as a probability question?
Date: 17 Mar 2010 10:44:46
Message: <op.u9pu85j2mn4jds@phils>
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And lo On Wed, 17 Mar 2010 02:33:08 -0000, Jim Charter <jrc### [at] msn com>
did spake thusly:
> Phil Cook v2 wrote:
>
>> So taking the results you've given I'm just guessing you've got a
>> low-scoring class; or the 'wrong' answer grid you're using is very
>> similar to the 'correct' one.
>>
>
> Yes, a small, fixed number of wrong answers on the marking key would
> give the same result I suspect also. But it is interesting to me how
> intuitively we discount the possibility that the one high score is a
> random outcome, but rather the proof that the key is okay, or mostly
> okay, and the class is low scoring.
Ah, but that's psychology rather than probability ;-) But yes, I suspect
it's because we're used to clusters cropping up naturally. When an extreme
appears we assume intention. If it had been a really low score would you
have taken that as proof that the key was wrong?
--
Phil Cook
--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com
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