  This paper is an early version.
  We propose to generalise the notion of "ignoring" a random process as well as
the notions of informative and ignorable random processes in a very general
setup and for different types of inference (Bayesian or frequentist), and for
different purposes (estimation, prediction or testing). We then confront the
definitions we propose to mentions or definitions of informative and ignorable
processes found in the litterature. To that purpose, we provide a very general
statistical framework for survey sampling in order to define precisely the
notions of design and selection, and to serve to illustrate and discuss the
notions proposed.
