depends on whether you want to know the number of possible values in a
dsicrete scale then range = max-min+1, this can among other thing be
compared with the maximum possible range
however, if one has continuous data then range = max - min
eg the smallest tad pole is 0.1cm & the largest .5 cm. you don't reall
think the range is 1.4 cm - do you?
cheers
diana
On Thu, 4 Oct 2001, jeff rasmussen wrote:
> Dear statistically-enamored,
>
> There was a question in my undergrad class concerning how to define the
> range, where a student pointed out that contrary to my edict, the range was
> "the difference between the maximum & minimum". I'd always believed that
> the correct answer was the "difference between the maximum & minimum plus
> one"; and irrespective of what the students' textbook and also SPSS said
> (when I ran some numbers through it) I thought that was the commonly
> accepted answer. I favor the "plus one" account as I feel that it balances
> out the "minus one" of degrees of freedom and thus puts the Tao correctly
> in balance. I asked a colleague who also came up with the same answer.
> Below in I and II are answers from internet sites that also agree.
>
> There are also however some sites that define it nakedly as "the
> difference between the maximum & minimum"; my theory is that the Evil SPSS
> Empire bought them off as part of their plan for world domination....
>
> Finally, we have a waffler's answer in III below...
>
> Curious to hear what you think about this defining issue for our times.
>
> best,
>
> JR
>
>
> from http://www.cuny.edu/tony/edstat22.html
>
> I. Measures of Dispersion or Spread
>
> Range - is the difference between the highest and lowest values in a group
> of values plus one. For example, the range of the following group of values
> 60,70,80,90,100 is 41 and is calculated by subtracting the lowest value
> (60) from the highest value (100) = 40 plus 1 = 41.
>
>
>
>
> from http://www.uwsp.edu/psych/stat/5/CT-Var.htm#II1
>
> II. Range
>
> As we noted when discussing the rules for creation of a grouped frequency
> distribution, the range is given by the highest score in the distribution
> minus the lowest score plus one.
>
> R = XH - XL + 1
>
>
>
>
> from http://luna.cas.usf.edu/~rasch/stat.html
>
> III. Measures of Dispersion
>
> Range: The Inclusive Range is the highest score minus the lowest score in a
> distribution plus 1. If the highest score on an examination is 97 and the
> lowest score 65, the range is 33. The plus 1 correction captures the values
> from 97.49 to 64.50. The Exclusive Range is just the highest score minus
> the lowest score. In the above example 32.
>
>
>
>
>
>
> Jeff Rasmussen
> http://www.symynet.com
> website & graphic design
> quantitative software
> spirit of tao te ching paperback & taoism
>
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Dr. Diana Kornbrot
Reader in Mathematical Psychology
Associate Dean Research, Faculty of Health & Human Sciences
University of Hertfordshire
College Lane, Hatfield, Hertfordshire AL10 9AB, UK
voice: +44 0170 728 4626 fax: +44 0170 728 5073
email: [log in to unmask]
web: http://www.psy.herts.ac.uk/pub/D.E.Kornbrot/hmpage.html
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