Resumen
Distributional properties of spacings and exceedances based on progressive type II censored order statistics are investigated. Recurrence relations between moments of concomitants for the model of progressive type II censoring are given. We unify and extend some results on spacings, exceedances and concomitants for the model of progressive censoring.

Resumen
The random variables ?1,?2,…,?n are said to be exchangeable (or symmetric) if for each n, P{?1?x1,…,?n?xn}=P{??(1)?x1,…,??(n)?xn} for any permutation ?=(?(1),…,?(n)) of {1,2,…,n} and any xi?R, i=1,…,n, i.e. the joint distribution of ?1,?2,…,?n is invariant under permutation of its arguments. In this study, run statistics are considered in the situation for which the elements of an exchangeable sequence ?1,?2,…,?n are binary with possible values “1” (success) or “0” (failure). The exact distributions of various run statistics are derived using the fact that the conditional distribution of any run statistic given the number of successes is identical to the corresponding distribution in the independent and identically distributed case.