Douglas E. Appelt
07.12.2011
Referentin: Lena Groeben
Agenda
 Introduction
 English referring expressions
 An Example of planning referring expressions
 An overview of Kamp
 Reference and concept activation
 Mutual knowledge
 Intention
 Concept activation actions
 Axioms
Introduction
 Major goal of natural language generation:
develop a means of utterances, natural and as close as
possible to what humans would produce
 Human language is part of a coherent plan  satisfy
speakers goals
 Satisfy multiple goals at different communication levels
Satisfying multiple Goals
Satisfying multiple Goals
 Different combinations:

Referring and communicating additional information

Emotional attitude

Requesting and being polite
Overview of an utterance planner
KAMP (Knowledge and Modalities Planner)
 hierarchical planning systems
 Primary consideration: avoid dividing the language
planning task into two independent processes
 Planning at each level involves consideration of
linguistic rules and goal satisfaction
 What and how: continuum without sharp distinction
 Hierarchical planner
English referring expressions
 only planning singular, specific definite noun phrases
that do not contain explicit quantifiers
 intention recognition process
English referring expressions
 intentions underly uses of the noun phrase under
consideration

refer to a mutually known object

speaker has an implicit intention that the hearer
might identify a referent

speaker has an implicit intention that the hearer not
identify a referent
English referring expressions
 expressions in natural language that denote objects in
the world
 may be used to perform a variety of actions
 concept activation
An example of planning referring
expressions
An example of planning referring
expressions
An example of planning referring
expressions
 KAMP needs knowledge in 5 areas:
 Basic common-sense knowledge
 Basic knowledge about the objects in the domain
 Knowledge and mutual knowledge of the agents in the
domain
 Descriptions of actions and their physical and knowledge
state effects
 Basic axioms about knowledge
An example of planning referring
expressions
An example of planning referring
expressions
An example of planning referring
expressions
An example of planning referring
expressions
An example of planning referring
expressions
An overview of KAMP
 At least one other agent (multiagent planning)

cooperating
 Solving problems by using heuristic problem-solving
method
 Two descriptions of actions:
 Relating possible worlds
 Action summary
 Procedural network (two-dimensional data structure)
An overview of KAMP
An overview of KAMP
 Simulates how the agents plan
 „identifies“ with one of the agents
 Initial goal procedural networkprocess executed
repeatingly
 Using critics
Reference and concept activations






Planning referring
Evoke right concept for the hearer
Semantic reference
Violations
KAMP: concepts are intensional objects that denote
objects in different possible worlds
Rigid designator (like a proper name)
Mutual knowledge
 Copresence heuristics are needed to decide what type of
mutual knowledge
 Three sources of mutual knowledge:
 Common membership in a community of speakers
 Sharing physical proximity that enables the agents to
observe and observe each other observing
 Linguistic exchange of information
Mutual knowledge
 KAMP requires a logical representation of mutual
knowledge
 Pseudo-individual kernel of A and B  definition
 If A and B mutually know P than they mutually know that
they mutually know P
 Know(A,Know(B,Know(A,…)))
Intention
 Reasoning about intention crucial to utterance planning
 Two levels to describe an agent’s intentions
 Intend (A,P): A intends to bring it about that P
 IntendToDo(A,act) means that A intends to perform act
 Axiom 3 und 4 if an agent intends to perform an action
then he intends to bring about the effects of the action
 Make simple multiple-agent plans
Concept activation actions
Concept activation actions
Concept Activation
 Level below surface speechs acts
 KAMP: concept part of mutual knowledge
 Realization as noun phrases
Axioms
 1) and 2) definition of mutual knowledge
 3) Semantics of intend
 4)Intend to do
 5) to 7) work together to achieve desired
communicative effects