The Virtual FM

Following [1], the fish market can be described as a place where several scenes take place simultaneously, at different locations, but with some causal continuity. The main scene is the auction itself, in which buyers bid for boxes of fish that are presented by an auctioneer who calls prices in descending order, the downward bidding protocol. However, before those boxes of fish may be sold, fishermen have to deliver the fish to the fish market, at 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.

The FM electronic auction house is based on this traditional fish market metaphor. In a highly mimetic way, the workings of FM also involve the concurrency of several scenes governed by the market intermediaries identified in the fish market (boss, buyer admitter, buyer manager, auctioneer, seller admitter, seller manager). Therefore, seller agents register their goods with a seller admitter agent, and can get their earnings (from a seller manager) once the auctioneer has sold these goods in the auction room. Buyers, on the other hand, register with a buyer admitter, and bid for goods which they pay through a credit line that is set up and updated by a buyer manager. Buyer and seller agents can trade goods as long as they comply with the institutional --auction market-- conventions.

The Virtual FM  attempts at offering a visual representation of the distributed workings of FM. Hence it has been divided into a set of scenes (out of market, buyers' admission, sellers' admission, auction room, buyers' settlements, and sellers' settlements) corresponding to their counterparts in FM. Within this setting, two representation levels can be differentiated:

• Global (Macro). Represents the agent flow (i.e., the flow of agents from scene to scene) and the events taking place during a bidding round.
• Local (Micro). Represents two levels of agent communication:
  • Intra-scene. Illocutions exchanged between the traders (buyers or sellers) placed in a scene and the market intermediary governing that scene.
  • Inter-scene. Illocutions exchanged between market intermediaries situated within different scenes.
  Anyhow, each agent's local information can be easily displayed by clicking on the icon representing the agent to be observed, and then a window similar to that on the left in Table in page will be ideally showed. Clicking again on the icon lets us browse all the messages sent and received by the selected agent as shown by the figure on the right in Table .

During each bidding round composing an auction of a tournament session, several events may come about: bids, collisions, sales, etc. These events are graphically represented by illuminating with different colours the icons of the agents involved in a given event. Find below the list of colours employed and their associated meanings:

1. Purple.: Bid submission. The agent's icon is labelled with a message of the type ``B: price'' accounting for the bid already submitted;
2. Red.: Penalty caused by an unsupported bid submission (the agent did not have enough credit to support his bid). The agent's icon is labelled with a message of the type ``F: penalty;
3. Green. Sale. The agent acquires the good in auction and his icon is labelled with the amount of accumulated purchases ``G: purchases''.
4. Yellow.The agent takes part in a collision.

Also note that no buyer is illuminated when the auctioneer declares the good on sale out of market (because its reserve price has been reached). Nonetheless, the Monitoring Agent does signal this event.

In what follows, the interaction through the Monitoring Agent  configuration panel with the Virtual FM   is explained in detail.