Posted by
Bob Schacht-3 on
Sep 20, 2006; 12:31am
URL: http://spssx-discussion.165.s1.nabble.com/Association-between-two-nominal-variables-tp1071026p1071028.html
At 12:42 PM 9/19/2006, Dominic Lusinchi wrote:
>Kevin,
>
>For a 2X2 table you can use the Phi statistic, available in the Crosstab
>procedure under Statistics. Phi varies from 0 to 1: closer to 1, stronger
>the association. Of course this assumes that the chi-square statistic is
>significant. . .
Of interest in this choice is whether the double null category is
meaningful-- that is, if Peer Pal is "no" (0) and the outcome labeled outpt
(for outpatient service received) is also no (0). If the double null is
meaningful and not merely a default, then the strength of Phi may depend
largely on how many double nulls there are. Is your sample population
defined in such a way that the double null applies to them differently than
to the 3 billion other people in the world for whom these two variables
have a value of 0?
If the double nulls are a poorly defined category, then you might want to
consider Jaccard's coefficient, which does not use the double nulls
(
http://en.wikipedia.org/wiki/Jaccard_index). It is extremely easy to
calculate.
Bob
Robert M. Schacht, Ph.D. <
[hidden email]>
Pacific Basin Rehabilitation Research & Training Center
1268 Young Street, Suite #204
Research Center, University of Hawaii
Honolulu, HI 96814