2.10 THE VARIOUS “EVENTS” ELEMENTS IN DATABASE TERMS what role a person or group has, the fundamental characteristics of an entity remain. The name, age, address, etc. of a victim will be the same even if he or she is performing the role of a source, but the nature of the link determines the role. Definition A link is a relationship between two entities. The link can be the traditional kind of relationship among persons, such as marriage or affiliation to an organisation (Biographic details link). It can also be embodied by a certain action or process. For instance, if one individual is the source of information about another, he is linked to the latter through the action of providing information. Link therefore constitutes an important concept additional to that of entity. To explain this more clearly, it would help to look again at Figure 2.3, reprinted below: ARREST OF DESACULA ET AL. EVENT Arrest Direct commission of act Detention PASAY POLICE FORCE Direct commission of act Arrest INTELLIGENCE AND SPECIAL OPERATIONS GROUP EDGAR DESACULA Direct commission of act Torture Direct comission of act RAMON AGUILAR Figure 2.3 Alternative graphical presentation of an event The boxes in the middle represent links between entities. The entities are the event and the various persons (individuals and groups) involved in the event, represented in this diagram by the boxes with shadows. For instance, Pasay Police Force and Edgar Desacula are two distinct person entities. Between them there could be various types of links. In this case however, the kind of link existing between the two has to do with violations, and therefore act and involvement represent this linkage. 19