Ontologies can support a variety of purposes,
ranging from capturing the conceptual knowledge
to the organisation of digital content and information.
However, information systems are always subject to
change and ontology change management can pose challenges.
In this sense, the application and representation
of ontology changes in terms of higher-level change operations
can describe more meaningful semantics behind
the applied change. In this paper, we propose a
fourphase process that covers the operationalization,
representation and detection of higherlevel changes in
ontology evolution life cycle. We present different levels
of change operators based on the granularity and
domainspecificity of changes. The first layer is based on
generic atomic level change operators, whereas the next
two layers are user-defined (generic/domainspecific) change
patterns. We introduce layered change logs for the explicit operational representation of ontology changes.
We formalised the change log using a graph-based approach.
We introduce a technique to identify composite
changes that not only assists in formulating ontology
change log data in a more concise manner, but
also helps in realizing the semantics and intent behind
any applied change. Furthermore, we identify frequent
change sequences that are applied as a reference in order
to discover reusable, often domainspecific and usagedriven
change patterns. We describe the pattern identification
algorithms and evaluate their performance.