Rational Effect

In FIPA-ACL, the effect a sender of a communicative act intends to bring about in the recipient (e.g. that the hearer come to believe a proposition). Because it concerns private mental state it is unverifiable, and is the principal target of critiques that call for grounded or social semantics.

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Backlinks

Trends in Agent Communication Language line 34

Linked Pages

Mentalistic Semantics

ACL semantics in which each message commits the sender’s (and sometimes receiver’s) beliefs and intentions — powerful but unverifiable from outside.

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FIPA-ACL

The Foundation for Intelligent Physical Agents Agent Communication Language — a standardised successor to KQML, defining performatives with mentalistic semantics (beliefs/intentions of sender and receiver).

Discussed in

Trends in Agent Communication Language

Reference: Chaib-draa, B., Dignum, F. (2002). Computational Intelligence, Vol. 18, No. 2. Source file: trends-in-acl.pdf. URL

Summary

Editorial introduction to a special issue on ACLs that surveys the field’s major research threads. The authors review the origins of ACLs (KSE, KQML/KIF, FIPA-ACL based on ARCOL), situating them as intentional/social layers above transport protocols (TCP/IP, HTTP, IIOP). They highlight five core issues: theories of agency underpinning the semantics, ACL semantics proper (pre-/post-/completion conditions vs. rational effects), verification of compliance and protocols, treatment of ontologies, and completeness of message-type sets.

The paper emphasizes tensions between mentalistic semantics (inherited from Searle/Cohen-Levesque speech-act theory) and social alternatives (Singh), and argues conversation policies/protocols are a primary practical vehicle for tractable agent interaction. It closes by reviewing ad-hoc treatment of ontologies and the limits of KQML and FIPA-ACL message-type coverage (e.g., missing commissives in FIPA-ACL).

Key Ideas

ACLs operate at intentional/social layer above transport.
Mentalistic (FIPA) vs. social (Singh) semantics tension.
Verifiability of sincerity/semantics is largely infeasible.
Conversation policies make ACL use tractable.
Ontology integration remains largely ad-hoc.

Connections

Conceptual Contribution

Claim: ACL research clusters around five persistent issues — theory of agency, ACL semantics, verification, ontologies, and completeness of message-type repertoires — and progress requires reconciling mentalistic and social semantics via practical conversation policies.
Mechanism: Chaib-draa and Dignum trace ACLs from the KSE through KQML/KIF to FIPA-ACL/ARCOL, situating them as an intentional/social layer above TCP/HTTP/IIOP transports, and survey each issue. They highlight Cohen–Levesque rational-effect semantics vs. Singh’s social commitments, argue sincerity verification is generally infeasible, note FIPA-ACL’s missing commissives, and promote conversation policies as the practical tractability lever.
Concepts introduced/used: ACL Layering, Rational Effect, Conversation Policy, Protocol Verification, Commissives, Theory of Agency, Ontology Grounding
Stance: survey
Relates to: A companion to The State of the Art in Agent Communication Languages; summarises the tension sharpened in Agent Communication Languages - Rethinking the Principles and motivates the commitment-based turn realised in An Interaction-oriented Agent Framework for Open Environments; its ontology concern links to Ontology Change Classification and Survey.