On Wed, 15 Aug 2001, Silvert, Henry wrote:
> I would like to add that with this kind of data
[three ordered categories per item, scored {3,2,1}]
> we use the median instead of the average.
I cannot resist pointing out two things:
(1) At the level of individual items, the median of three ordered
categories is pretty imprecise UNLESS one makes some interesting
assumptions about the scale values that are tantamount to treating them
as interval data;
(2) If the items are summed into a total score, they are being treated
as interval (and the total is a fortiori interval).
In either case, it is not clear whether the additional effort involved
in calculating medians (and their standard errors?), rather than means
etc., is worth one's while...
------------------------------------------------------------------------
Donald F. Burrill [EMAIL PROTECTED]
184 Nashua Road, Bedford, NH 03110 603-471-7128
=================================================================
Instructions for joining and leaving this list and remarks about
the problem of INAPPROPRIATE MESSAGES are available at
http://jse.stat.ncsu.edu/
=================================================================
