  Most approaches for repairing description logic (DL) ontologies aim at
changing the axioms as little as possible while solving inconsistencies,
incoherences and other types of undesired behaviours. As in Belief Change,
these issues are often specified using logical formulae. Instead, in the new
setting for updating DL ontologies that we propose here, the input for the
change is given by a model which we want to add or remove. The main goal is to
minimise the loss of information, without concerning with the syntactic
structure. This new setting is motivated by scenarios where an ontology is
built automatically and needs to be refined or updated. In such situations, the
syntactical form is often irrelevant and the incoming information is not
necessarily given as a formula. We define general operations and conditions on
which they are applicable, and instantiate our approach to the case of
ALC-formulae.
