At 10:40 AM 8/26/01 -0500, Olsen, Chris wrote:
>Dear Sir or Madam:
>
> I read with interest your posting on the issue of the so-called Tukey
>boxplot. I would like to make a few observations, if you will forgive the
>temerity of a high school teacher.
since i was not the person posting the original item on this matter ... i
do know in fact what the real purpose was for this particular item and, i
do not know what the mass. objectives are ... and the material presented in
typical classes ... that then finds its way on to the assessment test
i would say however ... that IF the test included only 6 items related to
statistics ... out of the larger test ... then the issue of whether in a
boxplot ... the vertical bar ... or .. in old minitab a + ...
Boxplot
---------------------------
-------------I + I-----------
---------------------------
+---------+---------+---------+---------+---------+------C1
-1.80 -1.20 -0.60 0.00 0.60 1.20
is the mean or median ... is trivial no matter what state the test is for ...
IF indeed there is an item on the test related to a boxplot ... then it
should be about interpreting data using the boxplot ... not about some
ditzy little tidbit that the line in the center part ... or the + sign
above ... is the mean or the median ...
by the way ... i think the original item used vertical bar or line ... in
the stem ... but, if one were using the graphic display above ... which is
perfectly legit ... then there is no vertical line or bar ... what would an
examinee do in that case???
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