 
% Mobility is an important precondition for many aspects of modern life like
% economic
% growth. But associated with increasing mobility is increasing traffc noise. 
% The research network "Quiet traffic" sponsored by the "Bundesministerium
% f\"ur Bildung und Forschung" (BMBF) examines among others things the 
% effect of transportation
% noise on humans, specifically the mental and physical health
% (Griefahn et al. 2005).
% We analyze a data set from the 1st preliminary study.
% 72 subjects are exposed
% twice to two different noise sources (i.e. road and rail noise) with 
% four different
% noise levels (40, 52, 70 and 82 [dB]) (Kuhnt et al. 2004). 
% The subjects judge the
% level of annoyance for the traffc noise on a scale which can be subsumized into ¯ve
% different levels (i.e. very high, high, moderate, low, very low). 
% The resulting data
% set is given in table  
% 
%    2nd exposure annoyance
% low ... high
% 51 28 3 0 0
% 15 68 40 5 1
% 0 29 77 21 1
% 0 4 19 80 14
% 0 1 5 26 88
% 
%(rows are 1st exposure)
% 
% We are interested in whether the subjects classify noise 
% differently when they are
% exposed to it twice, thus we test for symmetry. Several expected 
% values of this data
% are very small or even equal zero. Hence the chi2 approximation 
% of the distribution
% of the test statistic should be questioned.
   
 data=[ 51 28 3 0 0; ...
            15 68 40 5 1; ...
             0 29 77 21 1; ...
             0 4 19 80 14; ...
             0 1 5 26 88];
   
   stat =bowker(data )      
  

   
        
         
         
         
