Information state and dialogue management in the TRINDI

Dialogue Move Engine Toolkit, Larsson and Traum 2000

D&QA Reading Group, Feb 20th 2007Genevieve Gorrell

Information State Approach

Information state comprises cumulative additions from previous actions in the dialogue

“Superset” of finite state approaches since the state can easily be characterised as the information state but the information state is too rich to be rendered as a tractable finite state representation

Richer than structural approaches, more transparent than plan-based approaches ...

Information state theory of dialogue comprises

Informational components

Formal representation of the informational components

Dialogue moves

Update rules

Update strategy

Informational Components

Choose your own theory BDI?

Static/dynamic distinction may prove useful

Dialogue Gameboard (Ginzburg) Private/shared elements

Formal Representations of Informational Components

Simple abstract data types, logics, statistical systems ...

Lists, sets, stacks etc.

Dialogue Moves

A representation of the input/whatever you are going to update based on

Abstracts about the meaning/intention of the input

A variety of taxonomies exist

Logical forms etc.

Update Rules

Formalise information state update

Comprise applicability conditions

effects

Update Strategy

How to apply the rules? Take the first rule that applies

Apply each rule (if applicable) in sequence

Apply rules according to class

Choose among applicable rules using probabilistic information

Present choices to user to decide (for development modes)

Example

System has agenda item to ask user's destination

This meets conditions for update rule that selects “ask” move

System asks the question and applies the integrate rule shown earlier

Rule moves the question from the private agenda to the shared questions under discussion

Sys: Where do you want to go?Usr: Malvern

What is TRINDIKIT?

TRINDIKIT is a dialogue move engine toolkit

Provides basic architecture

Provides facilities for implementing theories of information state

Does not provide: User interface

Interpretation

Generation

Control

Example Architecture

Architecture cont.

Total Information State (TIS)

Information State

Hookups to additional resources

Dialogue Move Engine (DME)

One or more DME modules

DME-external modules

Control module, synchronous or asynchronous

TRINDIKIT also provides ... Datatype definitions

Language and format for TIS update rules

Methods for accessing the TIS

Algorithm definition language for DME and control modules

Default modules for input, interpretation, generation and output

Methods for converting items from one type to another (?)

Methods for visually inspecting the TIS

Debugging

GoDiS 1 Simple grounding phenomena

Question accommodation

Task accommodation

8 dialogue move types

ask, answer, repeat, request_repeat, greet, goodbye, thank, quit

Private, shared distinction in IS

shared information has been explicitly established in the dialogue

GoDiS 2 Shared information comprises:

propositions

questions under discussion

latest dialogue move (speaker, move type, content)

Private information comprises beliefs

agenda

plan (actions that are long term goals, editable during dialogue. How is this different to the agenda?)

tmp (mirrors shared fields, however information is not yet grounded)

GoDiS—Accommodation 1

Sys: Welcome to the travel agency!Usr: flights to parisSys: What city do you want to go from?

GoDiS—Accommodation 2

If the answer A is the answer to a question Q that it is in the plan to raise, then delete that question from the private plan and add the question to the shared questions under discussion (?)

GoDiS Update Algorithm

Rule types comprise refill, grounding, integrate, accommodate, database and store

EDIS 1

Information state comprises:

common ground obligations social commitments dialogue history conditional statements

semi-public grounded discourse units

private intentions

EDIS 2

Current and previous discourse units are included

Ungrounded discourse units feature

EDIS Update Algorithm Create new DU, add to UDUs

Set CDU to the new DU, set PDU to CDU

Perform updates on the basis of backward grounding acts

If any other type of act is observed

add to dialogue history

execute appropriate update rule(s)

Apply update rules to all parts of the IS with newly added acts

Other TRINDIKIT Systems—MIDAS

Discourse Representational Structures

Grounding tracking a la Poesio & Traum

Other TRINDIKIT Systems—Autoroute (Lewin)

Conversational games formalised as recursive transition networks

Discussion

How applicable is the accommodation work in more complex domains?

Would the work port to a conversational domain?

what would be the key issues?

In what ways can machine learning be incorporated?

Is there anything missing?