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Introduction to the TrindiKit. Dialogue Systems 2 GSLT spring 2003 Staffan Larsson sl@ling.gu.se. What is TrindiKit?. a toolkit for building and experimenting with dialogue move engines and systems, based on the information state approach not a dialogue system!. This lecture.
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Introduction to the TrindiKit Dialogue Systems 2 GSLT spring 2003 Staffan Larsson sl@ling.gu.se
What is TrindiKit? a toolkit for building and experimenting with dialogue move engines and systems, based on the information state approach not a dialogue system!
This lecture • architecture & concepts • what’s in TrindiKit? • extending TrindiKit • building a system
control DME module1 module… modulei modulej module… modulen • Total Information State • (TIS) • Information state proper (IS) • Module Interface Variables • Resource Interface Variables resource1 resource… resourcem
Information State (IS) • an abstract data structure (record, DRS, set, stack etc.) • accessed by modules using conditions and operations • the Total Information State (TIS) includes • Information State proper (IS) • Module Interface variables • Resource Interface variables
Dialogue Move Engine (DME) • module or group of modules responsible for • updating the IS based on observed moves • selecting moves to be performed • dialogue moves are associated with IS updates using IS update rules • there are also update rules no directly associated with any move (e.g. for reasoning and planning) • update rules: rules for updating the TIS • rule name and class • preconditon list: conditions on TIS • effect list: operations on TIS • update rules are coordinated by update algorithms
Modules and resources • Modules (dialogue move engine, input, interpretation, generation, output etc.) • access the information state • no direct communication between modules • only via module interface variables in TIS • modules don’t have to know anything about other modules • increases modularity, reusability, reconfigurability • may interact with user or external processes • Resources (device interface, lexicons, domain knowledge etc.) • hooked up to the information state (TIS) • accessed by modules • defined as object of some type (e.g. ”lexicon”)
What does TrindiKit provide? • High-level formalism and interpreter for implementing dialogue systems • promotes transparency, reusability, plug-and-play, etc. • allows implementation and comparison of dialogue theories • hides low-level software engineering issues • GUI, WWW-demo • Ready-made modules and resources • speech • interfaces to databases, devices, etc. • reasoning, planning
TrindiKit contents (1) • alibrary of datatype definitions (records, DRSs, sets, stacks etc.) • user extendible • alanguage for writing information state update rules • GUI: methods and tools for visualising the information state • debugging facilities • typechecking • logs of communication modules-TIS • etc.
TrindiKit contents (2) • A language for defining update algorithms used by TrindiKit modules to coordinate update rule application • A language for defining basic control structure, to coordinate modules • A library of basic ready-made modules for input/output, interpretation, generation etc.; • A library of ready-made resources and resource interfaces, e.g. to hook up databases, domain knowledge, devices etc.
Special modules and resources included with TrindiKit • OAA interface resource • enables interaction with existing software and languages other than Prolog • Speech recognition and synthesis modules • TrindiKit shells for off-the-shelf recognisers • currently only ViaVoice, but more on the way • Possible future modules: • planning and reasoning modules • multimodal input and output
Asynchronous TrindiKit • Internal communication uses either • OAA (Open Agent Architecture) from SRI, or • AE (Agent Environment), a stripped-down version of OAA, implemented for TrindiKit • enables asynchronous dialogue management • e.g.: system can listen and interpret, plan the dialogue, and talk at the same time
How to use TrindiKit We start from TrindiKit Implements the information state approach Takes care of low-level programming: dataflow, datastructures etc. TrindiKit information state approach
How to build a basic system Formulate a basic dialogue theory Information state Dialogue moves Update rules Add appropriate modules (speech recognition etc) basic dialoguetheory basic system TrindiKit information state approach
How to build a genre-specific system Add genre-dependent IS components, moves and rules genre-specific theory additions genre-specific system basic dialoguetheory basic system TrindiKit information state approach
How to build an application Add application-specific resources application domain & language resources genre-specific theory additions genre-specific system basic dialoguetheory basic system TrindiKit information state approach
Building a domain-independent Dialogue Move Engine • Come up with a nice theory of dialogue • Formalise the theory, i.e. decide on • Type of information state (DRS, record, set of propositions, frame, ...) • A set of dialogue moves • Information state update rules, including rules for integrating and selecting moves • DME Module algorithm(s) and basic control algorithm • any extra datatypes (e.g. for semantics: proposition, question, etc.)
Domain independence of the Dialogue Move Engine • The DME is domain independent, given a certain type of dialogue • information-seeking • instructional • negotiative • ... • Domain independence of DME is not enforced by TrindiKit, but is good practice • promotes reuse of components • forces abstraction from domain-specific details, resulting in a more general theory of dialogue
Specifying Infostate type • the Total Information State contains a number of Information State Variables • IS, the Information State ”proper” • Interface Variables • used for communication between modules • Resource Variables • used for hooking up resources to the TIS, thus making them accessible from to modules • use prespecified or new datatypes
sample infostate type declaration infostate_variable_of_type( is, IS ) :- IS = record( [ private : Private, shared : Shared ] ), Shared = record( [ com : set( proposition ), qud : stack( question ), lm : set( move ) ] ), Private = record( [ agenda: stack( action ), plan : stackset( action ), bel : set( proposition ), tmp : Shared ] ) ] ).
resulting infostate type AGENDA : stack( Action ) PLAN : stackset( Action ) PRIVATE : BEL : set( Prop ) TMP : (same type as SHARED) COM : set( Prop ) QUD : stack( Question ) SHARED : LU: [SPEAKER:dp, MOVES:set( Move )]
Sample interface variable type declarations interface_variable_of_type( input, string ). interface_variable_of_type( output, string ). interface_variable_of_type( latest_speaker, speaker ). interface_variable_of_type( latest_moves, set(move) ). interface_variable_of_type( next_moves, set(move) ).
Specifying a set of moves • amounts to specifying objects of type move (a reserved type) • there may be type constraints on the arguments of moves • preconditions and effects of moves • formalised in update rules, not in the move definition itself • a move may have different effects on the IS depending e.g. on who performed it
sample move specifications % Social of_type( quit, move ). of_type( greet, move ). of_type( thank, move ) . % Q&A of_type( ask(Q), move ) <- of_type( Q, question ). of_type(inform(P), move ) <- of_type( P, proposition). of_type( answer(R), move ) <- of_type( R, proposition) or of_type( R, ellipsis ).
Writing rules • rule = conditions + updates • if the rule is applied to the IS and its conditions are true, the operations will be applied to the IS • conditions may bind variables with scope over the rule (prolog variables, with unification and backtracking)
A sample rule rule( integrateUsrAnswer, [ $/shared/lu/speaker = usr, assoc( $/shared/lu/moves, answer(R), false ), fst( $/shared/qud, Q ), $domain : relevant_answer( Q, R ), $domain : reduce(Q, R, P) ], [ set_assoc( /shared/lu/moves, answer(R),true), shared/qud := $$pop( $/shared/qud ), add( /shared/com, P ) ] ).
A sample rule (old syntax) • rule( integrateUsrAnswer, [ • val#rec( shared^lu^speaker, usr ), • assoc#rec( shared^lu^moves, answer( R ), false ), • fst#rec( shared^qud, Q ), • domain :: relevant_answer( Q, R ), • domain :: reduce(Q, R, P) • ], [ • set_assoc#rec( shared^lu^moves, answer(R),true), • pop#rec( shared^qud ), • add#rec( shared^com, P ) ] ).
Writing rules • available conditions and operations depend on the infostate type • the infostate is declared to be of a certain (usually complex) type • datatype definitions provide • selectors: Sel(InObj,SelObj) • relations:Rel(Arg1, …, ArgN) • functions:Fun(Arg1, …, ArgN,Result) • operations: Op(ObjIn,Arg1, …, ArgN,ObjOut) • New datatypes may be added
Writing rules: locations in TIS • objects may be specified by giving a path to a locationin the infostate; • paths are specified using selectors, which are similar to functions • $$Sel2($$Sel1) ~ $Sel1/Sel2 • $$fst($/shared/qud) ~ $/shared/qud/fst • ”$” evaluates a path and gives the object at the location specified • ”$$” evaluates a function • $$fst($/shared/qud) = $/shared/qud/fst • example: • is/shared/com is a path, pointing to a location in the TIS • $is/shared/com is the object in that location • theiscan be left out, giving$/shared/com
Writing rules: conditions (1) • conditions do not change the information state • if a condition fails, backtracking ensues • condition syntax (incomplete) • Rel(Arg1, … , ArgN), e.g. • fst($/shared/qud,Q) • Arg1:Rel(Arg2,…,ArgN), e.g. • $/shared/qud:fst(Q) • $domain:relevant_answer(Q,A) • Arg1 = Arg2 • Q = $$fst($/shared/qud) • Cond1 and Cond2 • Cond1 or Cond2 • not Cond1 • forall(Cond1, Cond2) • (Argis object or prolog variable)
Writing rules: conditions (2) • quantification, binding and backtracking • if an instantiation a of a variable V in a condition C is found that makes condition C true, V is bound to a • backtracking occurs until a successful instantiation of all variables in the list of conditions has been found • example list of conditions fst($/shared/qud,Q), in($/shared/com,P), $domain:relevant_answer(P,Q) • Explicit quantification Q.P. fst($/shared/qud,Q) & in($/shared/com,P) & $domain:relevant_answer(P,Q)
Writing rules: updates • operations change the information state • if an operation fails, an error is reported • variable bindings survive from conditions to operations • operation syntax (incomplete) • Op(Path,Arg1,…,ArgN) • push(/shared/qud, Q) • Path : Op(Arg1, … ,ArgN) • /shared/qud : push(Q) • Store := Fun(Obj,Arg1,…,ArgN) • /private/tmp/qud := $$push($/shared/qud,Q)
Specifying update algorithms • uses rule classes • constructs include • Rule • RuleClass • if Cond then S else T • repeat R until C • repeat R • try R • R orelse S • test C • SubAlgorithm
Sample update algorithm grounding, if $latest_speaker == sys then try integrate, try database, repeat downdate_agenda, store else repeat integrate orelse accommodate orelse find_plan orelse if (empty ( $/private/agenda ) then manage_plan else downdate_agenda repeat downdate_agenda if empty($/private/agenda)) then repeat manage_plan repeat refill_agenda repeat store_nim try downdate_qud
Specifying serial control algorithms • serial constructs include • Module{:Algorithm} • if Cond then S else T • repeat R until C • repeat R • try R • R orelse S • test C • SubAlgorithm
Specifying concurrent control algorithms • Agent1 | Agent2 | … | AgentN • whereAgenti is • AgentName : { • import Module1 , • … • import Modulep , • Trigger1 => SerialAlgoritm1 , • … • Triggerm => SerialAlgoritmm } • triggers: • condition(C) (C is a subset of the full condition set) • init • new_data(Stream)
Sample control algorithm (1) repeat ( [ select, generate, output, update, test( $program_state == run ), input, interpret, update ] )
Sample control algorithm (2) input: { init => input:display_prompt, new_data(user_input) => input } | interpretation: { import interpret, condition(is_set(input)) => [ interpret, print_state ] } | dme: { import update, import select, init => [ select ], condition(not empty(latest_moves)) => [ update, if $latest_speaker == usr then select ] } | generation: { condition(is_set(next_moves)) => generate } | output: { condition(is_set(output)) => output } )).
From DME to dialogue system Build or select from existing components: • Modules, e.g. • input • interpretation • generation • output • Still domain independent • the choice of modules determines e.g. the format of the grammar and lexicon
Domain-specific system Build or select from existing components: • Resources, e.g. • domain (device/database) interface • dialog-related domain knowledge, e.g. plan libraries etc. • grammars, lexicons
You can add • Datatypes • Whatever you need • Modules • e.g. General interfaces to speech recognizers and synthesizers • Resources • E.g. General interfaces to (passive) devices • Important that all things added are reasonably general, so they can be reused in other systsems
Datatype definitions • relations • relations between objects; true or false • format: relation(Rel,Args). • Example • definition: relation(fst,[stack([E|S]),E]). • condition: fst($/shared/qud,Q)
Datatype definitions • functions • functions from arguments to result • format: function(Fun,Args,Result). • Example • definition: function(fst,[stack([E|S])],E). • in condition: • Q = $$fst($/shared/qud) • Q = $/shared/qud/fst • in effect: • next_move/content := $$fst($/shared/qud) • every function corresponds to a relation relation(Fun,[Args@[Result]]).
Datatype definitions (2) • selectors • selects an object (Obj) embedded in another object (Arg) • selector(Sel,Arg,Obj,ArgWithHole,Hole). • e.g. selector(fst,stack([E|S]),E,stack([H|S]),H). • Every selector corresponds to a function function(Sel,[Arg],Object).
Datatype definitions (3) • operations • operation(Op,InObj,Args,OutObj). • e.g. operation(push,stack(S),[E],stack([E|S])). • every operation corresponds to a relation relation(Op,[InObj|Args]@[OutObj]). • push($/shared/qud,Q,$/shared/qud).
Building modules • DME modules • Specific to a certain theory of dialogue management • Best implemented using rules and algorithms • Other modules • Should be more general, less specific to certain theory of dialogue management • May be easier to implement directly in prolog or other language • DME-ADL only covers checking and updating the infostate • These modules may also need to interact with other programs or devices