How to express interaction direction using Event Data model?

[zedomel]

One of the models we have discussed to share biotic interactions is the Event Data model. Basically, it uses dwc:Event class as core in the star schema to represent interactions, and then uses the same dwc:eventID to link two (or more?) dwc:Occurrence's together (ie. the interacting organisms).

One of the problems with that model is that we don't have how to capture the Interaction Type (e.g. visits Flower Of, eats, preys On), and also we don't have how to define the direction of the interaction (who eats who?, who visits who?).

We need meanings to specify which species/organisms are the source and the target. The dwc:ResourceRelationship looks that already provide it, since we can specify the subject and object of a relationship, and also the type of that relationship (ie. dwc:relationshipOfResource).

Should we adapt dwc:Event class or extend it (e.g. dwc:Interaction) in order to satisfy this requirements, or should we try another model (like dwc:ResourceRelationship)?