Evaluation Function (IV): Ordered Ag
for an ordered multivalued target variable Ag with values xi, a subgroup h is considered "unusual" if

5. the median of Ag in c(h) is significantly different from its median in r0

[med(X,S) := mÎS iff |{t in S | t[X]<m}| - |{t in S | t[X]>m}|=0 (or 1).]

   
Let m := med(Ag,c(h)), m0 := med(Ag,ro),  g = |c(h)| / |ro|  
      d(h):= g * (m - m0)                                    (0 if g < s0)