 proposition 1: agents need content  proposition 2: agents must provide added value  proposition 3: gestures and (facial) animation must be meaningful  proposition 4: agents should be naturally embedded in their environment  proposition 5: the behavior of agents must be understandable propositions

 remark 1: the aesthetics of agents should be centered around function, that is form and content  remark 2: developing agents requires intelligent multimedia technology remarks

 requirements -- guidelines for system design  applications -- target demonstrators  technology -- declarative programming  evaluation-- validation, PEFiC  conclusions and future research -- digital dossiers structure

 declarative language -- for agent support  multiple threads of control -- for multiple shared objects  distributed communication -- networking capabilities (TCP/IP) programming platform Requirements -- guidelines for system design  convenience -- for non-professional authors  compositional semantics -- combining operations  re-definability -- for high-level specification of actions  parametrization -- for the adaptation of actions  interaction -- with a (virtual) environment scripting behavior

Applications -- target demonstrators Agents in multi-user virtual environments Mixed-media presentations with commentators Tai-Chi, domestic servants and conducting music  tai-chi demonstrator  grasping and reaching, using inverse kinematics and reasoning  facial animation (with text-to-speech)  virtual presenter -- presenting powerpoint presentation STEP applications

Technology -- declarative programming DLP+X3D  control points: get/set -- position, rotation, viewpoint  event-handling -- asynchronous accept STEP  move -- move(Agent,BodyPart,Direction,Duration)  turn -- turn(Agent,BodyPart,Direction,Duration)  sequence -- [Action_1,...,Action_{n}]  parallel -- parallel([Action_1,...,Action_{n}])  choice -- disjunct([Action_1,...,Action_{n}])  repeat -- repeat(Action,k) composite operators

Evaluation -- validating agent-based applications Embodied agents as fictional characters phase 1 -- encoding  ethics -- good vs. bad  aesthetics -- beauty vs ugliness  epistemics -- realistic vs. unrealistic phase 2 -- comparison  establishing personal relevance, mutual similarity and valence towards fictional character phase 3 -- response  involvement vs distance -- tendency to approach or avoid PEFiC

Conclusions In this paper...  navigation -- pure interactivity  guided tours -- using some narrative structure  agent-mediated -- navigation and guided tours validation scenario(s) Future research directions