Page 278 - Socially Intelligent Agents Creating Relationships with Computers and Robots

Enabling Open Agent Institutions 261

bidding protocol. However, before those boxes of fish may be sold, fisher-
men have to deliver the fish to the fish market (in the sellers’ admission scene)
and buyers need to register for the market (at the buyers’ admission scene).
Likewise, once a box of fish is sold, the buyer should take it away by passing
through a buyers’ settlements scene, while sellers may collect their payments
at the sellers’ settlements scene once their lot has been sold.

3. Institution Components

In order to engineer open agent multi-agent systems as electronic institu-
tions we must firstly identify the core notions and components of electronic
institutions, the computational counterpart of institutions, taking inspiration on
the case study presented above. Thus our conception of electronic institution
shall be founded on the following concepts:
Agents and Roles. Agents are the players in an electronic institution, interact-
ing by the exchange of illocutions (speech acts), whereas roles are standardised
patterns of behaviour. Any agent within an electronic institution is required to
adopt some role(s). We fundamentally distinguish two classes of roles: insti-
tutional,and non-institutional.
Dialogical framework. In a dialogical institution, agents interact through il-
locutions. Institutions establish the ontology and the common language for
communication and knowledge representation, which are bundled in what we
call dialogical framework. By sharing a dialogical framework, we enable het-
erogeneous agents to exchange knowledge with other agents.
Scene. Interactions between agents are articulated through agent group meet-
ings, which we call scenes, with a well-defined communication protocol. We
consider the protocol of a scene to be the specification of the possible dia-
logues agents may have to articulate a multi-agent activity. A scene defines
a role-based framework of interaction for agents. A distinguishing feature of
scenes is that agents may join in or leave during the activity.
Performative structure. Scenes can be connected, composing a network of
scenes, the so-called performative structure, which captures the existing re-
lationships among scenes. A performative structure specifies how agents can
legally move from scene to scene by defining both the pre-conditions to join in
and leave scenes. Considering the fish market, while some activities like the
admission of buyers and sellers are completely independent, others are tightly
related. For instance, a buyer cannot bid for any good unless he has previously
and successfully set up a credit line.
Normative Rules. Agent actions in the context of an institution have con-
sequences, usually in the shape of compromises which impose obligations or
restrictions on dialogic actions of agents in the scenes wherein they are acting
or will be acting in the future. For instance, after winning a bidding round the