16. The method of claim 1 wherein at least one of the activities has an associated category that is not the category of any entity that is directly referenced by the content item but that is the category of an entity that is in a relationship with an entity that is directly referenced by the content item.
16. The method of claim 1 wherein at least one of the activities has an associated category that is not the category of any entity that is directly referenced by the content item but that is the category of an entity that is in a relationship with an entity that is directly referenced by the content item. 17. The method of claim 16 further comprising: traversing the links representing the is-a relations and member-of relations within the semantic network to identify the category that is associated with the at least one activity and that is not the category of any entity that is directly referenced by the content item but that is the category of the entity that is in a relationship with the entity that is directly referenced by the content item.