We put forward a methodological approach aimed at guiding ontology modellers in choosing which relations to reify. Our proposal is based on the notion of aggregation as used in conceptual modelling approaches for representing situations that, normally, would require nonbinary relations or complex integrity constraints. The feedback received from using the method in a real-word situation is that if offers a more controlled use of reification and a closer fit between the resulting ontology and the application domain as perceived by an expert.