hi karl ... i think the answer is yes ... if you want it to have 2 modes
the mode is a problematical statistic ... since there is no good definition
for it and ... a few frequencies shifting around ... could radically change
the "mode" or "modes"
in minitab, there is no place where ANY mode is even identified ...
i have heard about some software that report modes ... but, how they handle
multiple peaks with differing ns ... i have no idea
in the example you cite ... what if there were a spike at 12 hundredths ...
with = frequency to 10 ... would you call it bimodal ... or unimodal???
that is ... is there something of significance about the difference between
10 and 12 ... that we would want to separate them out as REALLY different
values? ... maybe it is still mono modal
a former student and now a academic vice president .. i know, a demotion!
... coined a new term for when you had two adjacent values ... each with
the highest frequency in the distribution ... he said take the median of
the two modes ... and call it the ...
MODIAN
At 12:54 PM 8/30/01 -0400, Wuensch, Karl L. wrote:
> Does a bimodal distribution necessarily have two modes? This might
>seem like a silly question, but in my experience many folks apply the term
>"bimodal" whenever the PDF has two peaks that are not very close to one
>another, even if the one peak is much lower than the other. For example,
>David Howell (Statistical Methods for Psychology, 5th, p. 29) presents
>Bradley's (1963) reaction time data as an example of a bimodal distribution.
>The frequency distribution shows a peak at about 10 hundredths of a second
>(freq about 520), no observations between about 18 and 33 hundredths, and
>then a second (much lower) peak at about 50 hundredths (freq about 25).
>
>+++++++++++++++++++++++++++++++++++++++++++++++++
>Karl L. Wuensch, Department of Psychology,
>East Carolina University, Greenville NC 27858-4353
>Voice: 252-328-4102 Fax: 252-328-6283
>[EMAIL PROTECTED]
>http://core.ecu.edu/psyc/wuenschk/klw.htm
>
>
>
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_________________________________________________________
dennis roberts, educational psychology, penn state university
208 cedar, AC 8148632401, mailto:[EMAIL PROTECTED]
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