This issue of SIGecom Exchanges includes five papers, two of which are survey papers.

The first paper, entitled "A Comparative Illustration of AI Planning-based Web Services Composition," presents a survey of how AI planning techniques could be used to combine multiple Web services to complete a single task.

The second paper is entitled "Propositional-Logic Approach to One-Shot Multi Issue Bilateral Negotiation." The paper posits the problem setting and the negotiation protocol in a logic-based framework, and illustrates its behavior on a simple example.

The third paper is another survey paper: "A Survey of Bargaining Models for Grid Resource Allocation." In spite of the fact that there has been little research in this direction to date, the author advocates bargaining as a mechanism for managing grid resources.

The fourth paper is entitled "A Comparison of Bidding Strategies for Simultaneous Auctions." This paper compares a set of heuristics, some old and some new, for bidding in simultaneous auctions on complementary and substitutable goods.

The fifth paper, entitled "A Rule-based Approach to Norm-Oriented Programming of Electronic Institutions," proposes a rule-based formalism to specify and manage the normative positions of agents, giving normative aspects a precise computational interpretation.

Amy Greenwald
Editor-in-Chief