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Kolmogorov-Smirnov test for nested alternatives?

To: "SPLUS_NEWS" <s-news@lists.biostat.wustl.edu>
Subject: Kolmogorov-Smirnov test for nested alternatives?
From: "Bill Shipley" <bill.shipley@usherbrooke.ca>
Date: Tue, 21 Feb 2006 10:06:53 -0500
Importance: Normal
Hello.  The Kolmogorov-Smirnov test in S-PLUS allows one to test for a significant deviation of an empirical distribution from a predicted distribution.  Consider a case where one has a series of nested alternative predicted distributions - alternative exponential distributions with increasing numbers of estimated parameters:
 
p(i) =(1/Z)exp(-lamda0 -lambda1*t_i1-lamda2*t_i2...)  where Z is a normalization constant and t_i1 etc are attributes of each group i and the lamda coefficients are estimated from the empirical data.
 
I would like to conduct a series of sequential tests in which
(I)
 I compare an empirical distribution of proportions over a set of groups to the predicted distributions assuming (1) all lamda values greater than 0 (i.e. lamda1, lamda 2 etc.) are zero; (2)all lamda values greater that 1 (i.e. lamda2, lamda3 etc.) are zero
 
(II) Compare the improvement in fit as I increase the number of lamda values that are freely estimated in order to detect non-significant improvement in fit.
 
Is it possible to do step (ii) using a Kolmogorov-Smirnov procedure? 

Bill Shipley 

 
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