  | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
   
   
    | • | 
    Tight
    coupling: applies to databases,
    systems 
     | 
     | 
   
   
     | 
   
   
     | 
    – | 
    Same address
    space, same process space, same operating 
     | 
     | 
   
   
     | 
    system, same
    machine 
     | 
     | 
   
   
     | 
   
   
     | 
    – | 
    Semantic
    compacts can be made because semantics stays in the 
     | 
     | 
   
   
     | 
    minds of the
    developers who agree 
     | 
     | 
   
   
     | 
   
   
    | • | 
    Loose
    coupling 
     | 
     | 
   
   
     | 
   
   
     | 
    – | 
    Different
    platforms, networks, anywhere on Internet 
     | 
     | 
   
   
     | 
   
   
     | 
    – | 
    Semantics must
    be explicit: agents, programs need to interpret the 
     | 
   
   
     | 
    semantics
    directly, to interoperate semantically 
     | 
     | 
   
   
     | 
   
   
     | 
    – | 
    Levels: systems
    of systems, enterprise, community, value 
     | 
     | 
   
   
     | 
    chains/pipes 
     | 
     | 
   
   
     | 
   
   
    | • | 
    Ontologies
    (explicitly represented, logical 
     | 
     | 
   
   
     | 
    semantics): increasingly needed the higher you 
     | 
     | 
   
   
     | 
    go 
     | 
     |