Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: nominal scale - comparison of populations
Replies: 3   Last Post: Dec 30, 2012 4:14 PM

 Messages: [ Previous | Next ]
 Paul Hightower Posts: 1 Registered: 12/23/12
Re: nominal scale - comparison of populations
Posted: Dec 23, 2012 6:47 PM

<czytaczgrup@gmail.com> wrote in message
Hi,

Using a short questionnaire I have interviewed two populations. For majority
of questions the answers are of the nominal type only (there are more than
two possible answers which are self excluding and complete). Now, I would
like to check if these populations are/are not the same with respect to the
as a distinct integer number. This gives me a probability distribution. Can
I use statistical tests to compare these distributions? If yes - would be
the outcome of a test robust to the way in which the numbers are adjusted?

---------------------------------------------------------------------------------------------------------
I really have no business commenting here, I am merely an introductory level
tutor. but your question might be elementary -- you have categorical data
such as (to take an example using automobiles) color, style, etc. For data
encoding purposes you may designate blue = 1, red =2, white = 3, etc. But to
treat this data as a single variable with ordinal or cardinal rank is
absurd. In what sense would white be 50% more than red and three times blue,
or even white > red > blue ? OK, you didn't mention rank, so presumably you
are aware of that.

Next, you can deal with proportions -- are there differences in colors among
different body stayles? I would attack such questions using chi-square
methods or perhaps ANOVA. Look up "test of homogeneity" in a standard stats
text, for example. Does that help?

Date Subject Author
12/23/12 czytaczgrup@gmail.com
12/23/12 Paul Hightower
12/23/12 Ray Koopman
12/30/12 czytaczgrup@gmail.com