Date: Fri, 14 May 2010 10:14:54 EDT
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: Marija Norusis <Marijaspss@aol.com>
Subject: Re: computing new variable based on percentiles
From the Transform Menu select Rank Cases then click on Rank Types. You can
create all sorts of groupings based on the ranks or you can select Ntiles
to create equal sized groups.
In a message dated 5/13/2010 4:44:38 P.M. Central Daylight Time,
try running frequencies with your variable (long printout as there is no
longer /format condense) then choose your cutting points according to where
you think they are in the cumulative frequencies column. Viewer panel is
free and no trees are felled!
recode oldvar (<range 1> = value1)(<range 2> = value2)(<range 3> = value3)
into newvar eg ( replace ? with your cutting points)
so you need to run something like:
freq testscore .
check the cumulative % column in your table and decide on your cutting
recode testscore (0 thru ? = 1)(? thru ? =2)(? thru ? = 3) etc etc (else =
sysmis) into testscoregrp.
Crude for perfectionists, but it works and saves your (and your funders')
time and finger-nails.
If you don't understand syntax, let me know and I'll send you a worked
example. It takes forever with the menus. It's the only use I can find for
the otherwise pointless default output column Cumulative Percent (which has
been there since the year dot, ie 1972 when I first used SPSS)
----- Original Message -----
From: _FernandezLanier, Adriana (DCJS)_
To: _SPSSX-L@LISTSERV.UGA.EDU_ (mailto:SPSSX-L@LISTSERV.UGA.EDU)
Sent: Wednesday, May 12, 2010 8:42 PM
Subject: computing new variable based on percentiles
Good afternoon. I hope my question makes sense. I was told that there is a
function in SPSS that will compute a new variable based on designated
percentiles (e.g., 25th, 75th). For example, I have a variable called “test
score” and I want to collapse/recode it into a variable that reflects low,
medium, and high (based on percentiles). I have searched but have not come
across any SPSS function that will compute a new variable. Any thoughts?
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