porder is taking all possible pairs (control=yes paired with each
control= no) and asking in what percent of those pairs is No larger than YES;
this does not appear to be the question you are asking; if I correctly
understand your question, I think you want a parametric procedure rather than
the rank-sum test
hope this helps
Rich
Óscar Becerra-CERAC wrote:
Hi all,
I am applying a Wilcoxon test for the equality of distributions, between two
control groups with the ranksum command. But I have a doubt about the
interpretation of the result of this test. The obtained result is:
ranksum series , by(control) porder
Two-sample Wilcoxon rank-sum (Mann-Whitney) test
control | obs rank sum expected
-------------+---------------------------------
NO | 2284 3280197 3338066
YES | 638 990306 932437
-------------+---------------------------------
combined | 2922 4270503 4270503
unadjusted variance 3.549e+08
adjustment for ties -5118462.8
----------
adjusted variance 3.498e+08
Ho: series(control==NO) = series(control==YES)
z = -3.094
Prob > |z| = 0.0020
P{series(control==NO) > series(control==YES)} = 0.460
According with the p - value, I understand that the distribution between –
groups changes, but I can’t understand the result obtained by the p order
option. What I really want to know is if when my control measure is on it
has a positive impact in the behaviour of series. Can you help me with this?
Thanks,
Óscar Becerra
Researcher
Conflict Analysis Resource Center
Carrera 10 N° 65 - 35 Of. 603
Tels: +(571) 345 85 72/3
www.cerac.org.co
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