  I comment on the relation between two sampling methods for absorbing state
models. It is shown that a certain ensemble without external field conditional
to activity coincides with the unconditional ensemble for sufficiently small
external field. The actual physical processes involved are identical and the
derivation of the identity of the scaling behaviour relies on a single
(established) scaling law. While the conditional ensemble by construction does
not contain information about the system with large external field, it contains
all information about the limit of vanishing external field and about the
vicinity of the critical point: Finite size scaling as well as critical scaling
in the temperature-like variable or in (small) external field.
