Dialogue Management as Intera tive Tree BuildingPeter LjunglöfPhilosophy, Linguisti s and Theory of S ien eUniversity of GothenburgDiaHolmia, 24�26 June 2009Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 1 / 26

Abstra tWe introdu e a new dialogue manager for limited-domaindialogue systems:the dialogue domain is spe i�ed in type theorythe user and system utteran es are spe i�ed as atype-theoreti al grammarThe dialogue manager tries to build a omplete type- orre t treeby su essive re�nement.similar to how Dynami Syntax builds an analysis of a senten ePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 2 / 26

Abstra tWe introdu e a new dialogue manager for limited-domaindialogue systems:the dialogue domain is spe i�ed in type theorythe user and system utteran es are spe i�ed as atype-theoreti al grammarThe dialogue manager tries to build a omplete type- orre t treeby su essive re�nement.similar to how Dynami Syntax builds an analysis of a senten ePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 2 / 26

Yet another dialogue managerSo, why a new dialogue manager?well-de�ned underlying logi (type-theory)all-in-one spe i� ation: the whole domain, both syntaxand semanti s, is spe i�ed within the same framework an use type- he king to ensure onsisten yPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 3 / 26

Simple type theoryThe types that are used in this talk are:basi types: A, B, C , . . .fun tions: T1 × · · · × Tn → TThe orresponding terms are: onstants: a1, a2, . . . : A, b1, . . . : B , . . .fun tions: f : T1 × · · · × Tn → Ti� f (t1, . . . , tn) : T whenever t1 : T1, . . . , tn : TnNote: in this framework we only use atomi fun tions (i.e., no lambdas).Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 4 / 26

Simple type theoryThe types that are used in this talk are:basi types: A, B, C , . . .fun tions: T1 × · · · × Tn → TThe orresponding terms are: onstants: a1, a2, . . . : A, b1, . . . : B , . . .fun tions: f : T1 × · · · × Tn → Ti� f (t1, . . . , tn) : T whenever t1 : T1, . . . , tn : TnNote: in this framework we only use atomi fun tions (i.e., no lambdas).Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 4 / 26

Dialogue as proof editingType Theory is based on the Curry-Howard isomorphism:type T ⇐⇒ proposition T ◦fun tion T1 × · · · × Tn → T ⇐⇒ impli ation T ◦1 ∧ . . . ∧ T ◦n → T ◦term t : T ⇐⇒ proof of T ◦building a term t : T ⇐⇒ proving a proposition T ◦An intera tive proof editor builds a term intera tively:metavariable ?T ⇐⇒ type (proposition) that has no term (proof)⇐⇒ question (from the system):�what is the proof for T ◦?�term ontaining metavariables ⇐⇒ in omplete proof treePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 5 / 26

Dialogue as proof editingType Theory is based on the Curry-Howard isomorphism:type T ⇐⇒ proposition T ◦fun tion T1 × · · · × Tn → T ⇐⇒ impli ation T ◦1 ∧ . . . ∧ T ◦n → T ◦term t : T ⇐⇒ proof of T ◦building a term t : T ⇐⇒ proving a proposition T ◦An intera tive proof editor builds a term intera tively:metavariable ?T ⇐⇒ type (proposition) that has no term (proof)⇐⇒ question (from the system):�what is the proof for T ◦?�term ontaining metavariables ⇐⇒ in omplete proof treePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 5 / 26

Spe ifying a theorySpe ifying a theory onsists of giving:the basi types (A tion, Pri e, Event, Date, City)the onstants (sthlm : City , today : Date, ¿450 : Pri e)the fun tions (book : Event → A tion, hotel : City × Date → Event)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 6 / 26

Spe ifying the utteran esTo ea h type, onstant and fun tion we have to spe ify utteran es:system questions orresponding to basi types(?A tion 7→ �What do you want to do?�,?Date 7→ �What date do you mean?�)utteran es orresponding to onstants:(sthlm 7→ �Sto kholm�, ¿450 7→ �fourhundred and �fty Euros�) omplex utteran es for fun tions:(book(x) 7→ �book (an event | x), please�,hotel(x , y) 7→ �a hotel ?(in x) ?(y)�)This means that �book a hotel, please� is interpreted asbook(hotel(?City , ?Date)).Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 7 / 26

An example domainA travel agen y: spe i�ed as in omplete treesbook(?Event),pri e(?Pri e),when(?Date) : A tionevent(?Event) : Pri eoneway(?Route, ?Date),return(?Route, ?Date, ?RDate),hotel(?City, ?Date), onferen e(?Conferen e) : Eventroute(?Dest, ?Dept, ?Means) : RoutereturnDate(?Date) : RDateto(?City) : Destfrom(?City) : Dept2009, 2010, . . . : Yearjan, feb, . . . : Month1st, 2nd, . . . : Daylon, sthlm, . . . : City�ight, boat, . . . : Meanssemdial, a l, . . . : Conferen e¿450, ¿600, . . . : Pri etoday, tomorrow,date(?Month, ?Day), onf-date(?Conferen e, ?Year) : DatePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 8 / 26

Terms and TreesAn example termbook(oneway(route(to(sthlm), from(lon), boat), tomorrow))) : A tion

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 9 / 26

Terms and TreesA fully typed variantbook(oneway(route(to(sthlm:City):Dest, from(lon:City):Dept,boat:Means), tomorrow:Date):Route):Event):A tion

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 9 / 26

Terms and TreesA fully typed variantbook(oneway(route(to(sthlm:City):Dest, from(lon:City):Dept,boat:Means), tomorrow:Date):Route):Event):A tionThe orresponding tree book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:DatePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 9 / 26

Dialogue management by su essive re�nementThe dialogue system builds a omplete tree by su essive re�nement.similar (but not equivalent) to how Dynami Syntax worksUninstantiated nodes in the tree are represented with typed metavariables:a metavariable of type T is written ?T as a wh-questionor ?f1 ∨ . . . ∨ fn : T for the orresponding alt-questionThere is always one a tive node in the urrent tree:it is alled the fo us node (and is highlighted)The tree is operated with ommands:moving fo us, inserting subtrees, re�nining metavariables, . . .The initial tree is the single fo used node ?A tion.Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 10 / 26

Dialogue management by su essive re�nementThe dialogue system builds a omplete tree by su essive re�nement.similar (but not equivalent) to how Dynami Syntax worksUninstantiated nodes in the tree are represented with typed metavariables:a metavariable of type T is written ?T as a wh-questionor ?f1 ∨ . . . ∨ fn : T for the orresponding alt-questionThere is always one a tive node in the urrent tree:it is alled the fo us node (and is highlighted)The tree is operated with ommands:moving fo us, inserting subtrees, re�nining metavariables, . . .The initial tree is the single fo used node ?A tion.Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 10 / 26

Dialogue management by su essive re�nementThe dialogue system builds a omplete tree by su essive re�nement.similar (but not equivalent) to how Dynami Syntax worksUninstantiated nodes in the tree are represented with typed metavariables:a metavariable of type T is written ?T as a wh-questionor ?f1 ∨ . . . ∨ fn : T for the orresponding alt-questionThere is always one a tive node in the urrent tree:it is alled the fo us node (and is highlighted)The tree is operated with ommands:moving fo us, inserting subtrees, re�nining metavariables, . . .The initial tree is the single fo used node ?A tion.Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 10 / 26

Dialogue management by su essive re�nementThe dialogue system builds a omplete tree by su essive re�nement.similar (but not equivalent) to how Dynami Syntax worksUninstantiated nodes in the tree are represented with typed metavariables:a metavariable of type T is written ?T as a wh-questionor ?f1 ∨ . . . ∨ fn : T for the orresponding alt-questionThere is always one a tive node in the urrent tree:it is alled the fo us node (and is highlighted)The tree is operated with ommands:moving fo us, inserting subtrees, re�nining metavariables, . . .The initial tree is the single fo used node ?A tion.Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 10 / 26

Dialogue management by su essive re�nementThe dialogue system builds a omplete tree by su essive re�nement.similar (but not equivalent) to how Dynami Syntax worksUninstantiated nodes in the tree are represented with typed metavariables:a metavariable of type T is written ?T as a wh-questionor ?f1 ∨ . . . ∨ fn : T for the orresponding alt-questionThere is always one a tive node in the urrent tree:it is alled the fo us node (and is highlighted)The tree is operated with ommands:moving fo us, inserting subtrees, re�nining metavariables, . . .The initial tree is the single fo used node ?A tion.Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 10 / 26

System-driven dialogue ?A tion

S: ask(?A tion) ⇒�What do you want to do?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue?pri e∨book:A tion

refine-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue?pri e∨book:A tion

S: ask(pri eIssue(?Pri e):A tion ∨ book(?Event):A tion) ⇒�Do you want to ask for the pri e or book an event?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue?pri e∨book:A tion

U: �book an event�⇒answer(book(?Event):A tion)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tion?Eventintegrate book(?Event):A tionPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tion?Eventsele t-nextPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tion?EventS: ask(?Event)⇒�What event are you interested in?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tion?oneway∨return∨hotel∨ onferen e:Eventrefine-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tion?oneway∨return∨hotel∨ onferen e:EventS: ask(oneway ∨ return ∨ hotel ∨ onferen e) ⇒�Oneway trip, return trip, hotel or onferen e?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tion?oneway∨return∨hotel∨ onferen e:EventU: �oneway trip� ⇒answer(oneway(?Route,?Date):Event)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Event?Route ?Dateintegrate oneway(?Route,?Date):EventPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Event?Route ?Datesele t-nextPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Event?Route ?DateS: ask(?Route) ⇒�Whi h route do you want?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Route?Dest ?Dept ?Means?Daterefine-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Route?Dest ?Dept ?Means?Datesele t-nextPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Route?Dest ?Dept ?Means?DateS: ask(?Dest) ⇒�To whi h ity are you heading?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Route?Dest ?Dept ?Means?DateU: �to Sto kholm� ⇒answer(to(sthlm:City):Dest)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?Dateintegrate to(sthlm:City):DestPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?Datesele t-nextPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?DateS: ask(?Dept) ⇒�From where are you leaving?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?DateU: �from London� ⇒answer(from(lon:City):Dept)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City ?Means?Dateintegrate from(lon:City):DeptPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City ?Means?Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Means?Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Means?Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

System-driven dialogue book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:DateVoilà!Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 11 / 26

Underspe i�ed tree nodesI have borrowed the idea of underspe i�ed (or un�xed) nodesfrom Dynami Syntax (or rather the Logi of Finite Trees):t:A tion?Ab:B :C ?De:EThe type A (D) must dominate B, C (E); i.e.: A ⇒∗ αBβ, . . .All dominating nodes (A, D) must be uninstantiatedPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 12 / 26

Underspe i�ed informationWe use underspe i�ed tree nodes for in orporating underspe i�edinformation; when the user says something whi h the system annotintegrate into the urrent tree.This is similar to how Dynami Syntax does it:◮ if the synta ti fun tion of a phrase is unknown,its node/tree be omes underspe i�ed◮ e.g., a noun in initial position an be subje t or obje tCorresponds to issue/a tion lari� ation in GoDiS◮ within plans or between plansThere are (at least) three di�erent re�nement strategies.Correspond to known dialogue strategies?Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 13 / 26

Strategy 1: Top-down re�nement?A tion

S: ask(?A tion) ⇒�What do you want to do?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nement?A tionroute:Routeto:Deststhlm:City ?Dept ?MeansU: �go to Sto kholm�⇒answer(route(to(sthlm),?City,?Means):Route)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nement?pri e∨book:A tionroute:Routeto:Deststhlm:City ?Dept ?MeansS: ask(pri eIssue(?):A tion ∨ book(?):A tion) ⇒�Do you want to ask for the pri e or book an event?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tion?Eventroute:Routeto:Deststhlm:City ?Dept ?MeansU: �book an event�⇒answer(book(?Event):A tion)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tion?oneway∨return:Eventroute:Routeto:Deststhlm:City ?Dept ?MeansS: ask(oneway(?,?):Event ∨ return(?,?,?):Event)⇒�Do you want a oneway trip or a return trip?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Event?Routeroute:Routeto:Deststhlm:City ?Dept ?Means?DateU: �oneway�⇒answer(oneway(?Route,?Date):Event)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?Daterefine-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?Datesele t-nextPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?DateS: ask(?Dept) ⇒�From where are you leaving?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Deptlon:City ?Means?DateU: �London�⇒answer(lon:City)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Dept?Citylon:City ?Means?Daterefine-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City ?Means?Daterefine-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City ?Means?Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Means?Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 1: Top-down re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 14 / 26

Strategy 2: Bottom-up re�nement?A tion

S: ask(?A tion) ⇒�What do you want to do?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tionroute:Routeto:Deststhlm:City ?Dept ?MeansU: �go to Sto kholm�⇒answer(route(to(sthlm),?Dept,?Means):Route)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tionroute:Routeto:Deststhlm:City ?Dept ?Means fo us-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tion?oneway∨return:Eventroute:Routeto:Deststhlm:City ?Dept ?Means refine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tion?oneway∨return:Eventroute:Routeto:Deststhlm:City ?Dept ?MeansS: ask(oneway(?,?):Event ∨ return(?,?,?):Event)⇒�Do you want a oneway trip or a return trip?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?DateU: �oneway�⇒answer(oneway(?Route,?Date):Event)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tion?pri e∨book:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?Daterefine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tion?pri e∨book:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?DateS: ask(pri eIssue(?):A tion ∨ book(?):A tion) ⇒�Do you want to ask for the pri e or book an event?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nement?A tionbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?DateU: �book an event�⇒answer(book(?Event):A tion)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?Daterefine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?Datesele t-nextPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Dept ?Means?DateS: ask(?Dept) ⇒�From where are you leaving?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Deptlon:City ?Means?DateU: �London�⇒answer(lon:City)Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Deptlon:City ?Means?Datefo us-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City ?Deptfrom:Deptlon:City ?Means?Daterefine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City ?Means?Daterefine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City ?Means?Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Means?Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 2: Bottom-up re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:Date(et etera. . . )Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 15 / 26

Strategy 3: �Bottom-down� re�nement?A tion

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City ?Dept ?Means

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City ?Dept ?Means

fo us-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City ?Dept ?Means

sele t-nextPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City ?Deptlon:City ?Means

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City ?Deptlon:City ?Means

fo us-downPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City ?Deptfrom:Deptlon:City ?Means

refine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City from:Deptlon:City ?Means

refine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City from:Deptlon:City ?Means

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionroute:Routeto:Deststhlm:City from:Deptlon:City boat:Means

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tion?oneway∨return:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meansrefine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Means?DatePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Means?DatePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:DatePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tion?pri e∨book:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:Daterefine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nement?A tionbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:DatePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Strategy 3: �Bottom-down� re�nementbook:A tiononeway:Eventroute:Routeto:Deststhlm:City from:Deptlon:City boat:Meanstomorrow:Daterefine-upPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 16 / 26

Three di�erent re�nement strategiesSo, there are (at least) the following re�nement strategies:top-down re�nementbottom-up re�nement�bottom-down� re�nementOf ourse, these strategies an be ombined, e.g.:strategy depends on the type of the dominating nodestrategy depends on the maximum/minimum distan e between thedominating and dominated nodesPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 17 / 26

Three di�erent re�nement strategiesSo, there are (at least) the following re�nement strategies:top-down re�nementbottom-up re�nement�bottom-down� re�nementOf ourse, these strategies an be ombined, e.g.:strategy depends on the type of the dominating nodestrategy depends on the maximum/minimum distan e between thedominating and dominated nodesPeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 17 / 26

Answering user questionsWe use fun tion de�nitions for �nding answers to user questions.when(?Date) : A tion onf-date(?Conferen e, ?Year) : Dateea l, semdial, . . . : Conferen edef onf-date(semdial,2009) = date(jun,24)def onf-date(semdial,2010) = . . .def onf-date(a l,2009) = . . .U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�⇒ when( onf-date(semdial,2009)) ⇒ when(date(jun,24)) ⇒S: �SemDial 2009 starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 18 / 26

Answering user questionsWe use fun tion de�nitions for �nding answers to user questions.when(?Date) : A tion onf-date(?Conferen e, ?Year) : Dateea l, semdial, . . . : Conferen edef onf-date(semdial,2009) = date(jun,24)def onf-date(semdial,2010) = . . .def onf-date(a l,2009) = . . .U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�⇒ when( onf-date(semdial,2009)) ⇒ when(date(jun,24)) ⇒S: �SemDial 2009 starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 18 / 26

Answering user questionsWe use fun tion de�nitions for �nding answers to user questions.when(?Date) : A tion onf-date(?Conferen e, ?Year) : Dateea l, semdial, . . . : Conferen edef onf-date(semdial,2009) = date(jun,24)def onf-date(semdial,2010) = . . .def onf-date(a l,2009) = . . .U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�⇒ when( onf-date(semdial,2009)) ⇒ when(date(jun,24)) ⇒S: �SemDial 2009 starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 18 / 26

Answering user questionsWe use fun tion de�nitions for �nding answers to user questions.when(?Date) : A tion onf-date(?Conferen e, ?Year) : Dateea l, semdial, . . . : Conferen edef onf-date(semdial,2009) = date(jun,24)def onf-date(semdial,2010) = . . .def onf-date(a l,2009) = . . .U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�⇒ when( onf-date(semdial,2009)) ⇒ when(date(jun,24)) ⇒S: �SemDial 2009 starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 18 / 26

Answering user questionsWe use fun tion de�nitions for �nding answers to user questions.when(?Date) : A tion onf-date(?Conferen e, ?Year) : Dateea l, semdial, . . . : Conferen edef onf-date(semdial,2009) = date(jun,24)def onf-date(semdial,2010) = . . .def onf-date(a l,2009) = . . .U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�⇒ when( onf-date(semdial,2009)) ⇒ when(date(jun,24)) ⇒S: �SemDial 2009 starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 18 / 26

Answering user questionsWe use fun tion de�nitions for �nding answers to user questions.when(?Date) : A tion onf-date(?Conferen e, ?Year) : Dateea l, semdial, . . . : Conferen edef onf-date(semdial,2009) = date(jun,24)def onf-date(semdial,2010) = . . .def onf-date(a l,2009) = . . .U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�⇒ when( onf-date(semdial,2009)) ⇒ when(date(jun,24)) ⇒S: �SemDial 2009 starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 18 / 26

Linked treesAn underspe i�ed node is (will be) a subtree of its parent nodein DS, underspe i�ed nodes are used when their fun tion is unknownhere, they are used for underspe i�ed/ambiguous user answersA linked tree is not dominated by its �parent�: it is a di�erent treein DS, linked trees are used for relative lauses, PPs, de�nites,anaphori expressions and su h things◮ links are hard: they determine the semanti s of the �parent�here, links are used for answers, sub-dialogues, anaphori expressions◮ links are soft: the user is free to skip the result of the sub-dialoguePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 19 / 26

Linked treesAn underspe i�ed node is (will be) a subtree of its parent nodein DS, underspe i�ed nodes are used when their fun tion is unknownhere, they are used for underspe i�ed/ambiguous user answersA linked tree is not dominated by its �parent�: it is a di�erent treein DS, linked trees are used for relative lauses, PPs, de�nites,anaphori expressions and su h things◮ links are hard: they determine the semanti s of the �parent�here, links are used for answers, sub-dialogues, anaphori expressions◮ links are soft: the user is free to skip the result of the sub-dialoguePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 19 / 26

Linked treest:A tion

?Aq:A tionlink-type

The information state of our proposed dialogue model is:a olle tion of linked trees,where one tree is a tive, and has an a tive fo us nodePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 20 / 26

Linked treest:A tion

?Aq:A tionlink-type

The information state of our proposed dialogue model is:a olle tion of linked trees,where one tree is a tive, and has an a tive fo us nodePeter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 20 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialoguesExample sub-dialogueU: �I'd like to book a boat to Sto kholm�S: �When do you want to leave?�U: �when is SemDial?�S: �Whi h year do you mean?�U: �this year�S: �SemDial starts 24th June.�U: �ok, I'll leave the day before�S: �I have booked a boat to Sto kholm on 23rd June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 21 / 26

Sub-dialogues?A tion

S: �What an I do for you?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date

U: �I want to book a boat to Sto kholm�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date

S: �When do you want to leave?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date when:A tion onf-date:Datesemdial:Conferen e ?Yearsub-dialog

U: �when is SemDial?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date when:A tion onf-date:Datesemdial:Conferen e ?Yearsub-dialog

U: �when is SemDial?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date when:A tion onf-date:Datesemdial:Conferen e ?Yearsub-dialog

S: �Whi h year do you mean?�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date when:A tion onf-date:Datesemdial:Conferen e 2009:Yearsub-dialog

U: �this year�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date when:A tion onf-date:Datesemdial:Conferen e 2009:Yearsub-dialog

S: �SemDial starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route ?Date when:A tion onf-date:Datesemdial:Conferen e 2009:Yearsub-dialog

S: �SemDial starts 24th June.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Sub-dialoguesbook:A tiononeway:Eventroute:Route date:Datejune:Month 23rd:Day

when:A tion onf-date:Datesemdial:Conferen e 2009:Yearsub-dialogU: �ok, I'll leave the day before�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 22 / 26

Anaphori expressions?A tionS: �What an I do for you?�U: �how mu h is a �ight to Sto kholm tomorrow?�S: �It osts ¿450.�U: �ok, book it�S: �I have booked a �ight to Sto kholm tomorrow.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 23 / 26

Anaphori expressionspri e:A tionevent:Pri eoneway:Eventroute:Route tomorrow:DateS: �What an I do for you?�U: �how mu h is a �ight to Sto kholm tomorrow?�S: �It osts ¿450.�U: �ok, book it�S: �I have booked a �ight to Sto kholm tomorrow.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 23 / 26

Anaphori expressionspri e:A tionevent:Pri eoneway:Eventroute:Route tomorrow:Datepri e:A tion¿450:Pri eanswer

S: �What an I do for you?�U: �how mu h is a �ight to Sto kholm tomorrow?�S: �It osts ¿450.�U: �ok, book it�S: �I have booked a �ight to Sto kholm tomorrow.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 23 / 26

Anaphori expressionspri e:A tionevent:Pri eoneway:Eventroute:Route tomorrow:Datepri e:A tion¿450:Pri e book:A tion?Eventanswer anaphori S: �What an I do for you?�U: �how mu h is a �ight to Sto kholm tomorrow?�S: �It osts ¿450.�U: �ok, book it�S: �I have booked a �ight to Sto kholm tomorrow.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 23 / 26

Anaphori expressionspri e:A tionevent:Pri eoneway:Eventroute:Route tomorrow:Datepri e:A tion¿450:Pri e book:A tion?Eventanswer anaphori S: �What an I do for you?�U: �how mu h is a �ight to Sto kholm tomorrow?�S: �It osts ¿450.�U: �ok, book it�S: �I have booked a �ight to Sto kholm tomorrow.�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 23 / 26

Several alternatives?A tionS: �What an I do for you?�U: �how mu h is a trip to Sto kholm tomorrow?�S: �By plane or by boat?�U: �both�S: �Plane osts ¿450 and boat ¿300.�U: �ok, book the heapest one�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 24 / 26

Several alternativespri e:A tionevent:Pri eoneway:Eventroute:Route· · · · · · ?Meanstomorrow:DateS: �What an I do for you?�U: �how mu h is a trip to Sto kholm tomorrow?�S: �By plane or by boat?�U: �both�S: �Plane osts ¿450 and boat ¿300.�U: �ok, book the heapest one�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 24 / 26

Several alternatives pri e:A tionevent:Pri eoneway:Eventroute:Route· · · · · · ?plane∨boat:Meanstomorrow:DateS: �What an I do for you?�U: �how mu h is a trip to Sto kholm tomorrow?�S: �By plane or by boat?�U: �both�S: �Plane osts ¿450 and boat ¿300.�U: �ok, book the heapest one�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 24 / 26

Several alternatives pri e:A tionevent:Pri eoneway:Eventroute:Route· · · · · · plane∨boat:Meanstomorrow:DateS: �What an I do for you?�U: �how mu h is a trip to Sto kholm tomorrow?�S: �By plane or by boat?�U: �both�S: �Plane osts ¿450 and boat ¿300.�U: �ok, book the heapest one�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 24 / 26

Several alternativespri e:A tionevent:Pri eoneway:Eventroute:Route· · · · · · plane∨boat:Meanstomorrow:Date

pri e:A tion¿450∨¿300:Pri eanswerS: �What an I do for you?�U: �how mu h is a trip to Sto kholm tomorrow?�S: �By plane or by boat?�U: �both�S: �Plane osts ¿450 and boat ¿300.�U: �ok, book the heapest one�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 24 / 26

Several alternativespri e:A tionevent:Pri eoneway:Eventroute:Route· · · · · · plane∨boat:Meanstomorrow:Date

pri e:A tion¿450∨¿300:Pri e book:A tion?Eventanswer heapestS: �What an I do for you?�U: �how mu h is a trip to Sto kholm tomorrow?�S: �By plane or by boat?�U: �both�S: �Plane osts ¿450 and boat ¿300.�U: �ok, book the heapest one�Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 24 / 26

SummaryThe dialogue system domain is spe i�ed in type theoryA dialogue manager an be implemented using intera tive tree buildingUn�xed tree nodes represent underspe i�ed informationLinked trees are used for sub-dialogue and anaphori expressionsFun tion de�nitions represent system answers to user questionsUser and system utteran es are spe i�ed in type-theoreti al grammar,ensuring onsisten y between surfa e form and internal representation

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 25 / 26

SummaryThe dialogue system domain is spe i�ed in type theoryA dialogue manager an be implemented using intera tive tree buildingUn�xed tree nodes represent underspe i�ed informationLinked trees are used for sub-dialogue and anaphori expressionsFun tion de�nitions represent system answers to user questionsUser and system utteran es are spe i�ed in type-theoreti al grammar,ensuring onsisten y between surfa e form and internal representation

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 25 / 26

SummaryThe dialogue system domain is spe i�ed in type theoryA dialogue manager an be implemented using intera tive tree buildingUn�xed tree nodes represent underspe i�ed informationLinked trees are used for sub-dialogue and anaphori expressionsFun tion de�nitions represent system answers to user questionsUser and system utteran es are spe i�ed in type-theoreti al grammar,ensuring onsisten y between surfa e form and internal representation

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 25 / 26

SummaryThe dialogue system domain is spe i�ed in type theoryA dialogue manager an be implemented using intera tive tree buildingUn�xed tree nodes represent underspe i�ed informationLinked trees are used for sub-dialogue and anaphori expressionsFun tion de�nitions represent system answers to user questionsUser and system utteran es are spe i�ed in type-theoreti al grammar,ensuring onsisten y between surfa e form and internal representation

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 25 / 26

SummaryThe dialogue system domain is spe i�ed in type theoryA dialogue manager an be implemented using intera tive tree buildingUn�xed tree nodes represent underspe i�ed informationLinked trees are used for sub-dialogue and anaphori expressionsFun tion de�nitions represent system answers to user questionsUser and system utteran es are spe i�ed in type-theoreti al grammar,ensuring onsisten y between surfa e form and internal representation

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 25 / 26

SummaryThe dialogue system domain is spe i�ed in type theoryA dialogue manager an be implemented using intera tive tree buildingUn�xed tree nodes represent underspe i�ed informationLinked trees are used for sub-dialogue and anaphori expressionsFun tion de�nitions represent system answers to user questionsUser and system utteran es are spe i�ed in type-theoreti al grammar,ensuring onsisten y between surfa e form and internal representation

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 25 / 26

What have I not dis ussed?Commands: whi h they are and how to de�ne themFeedba k: how it an be in orporatedCorre tions: ommands for deleting nodes in the treeDependent types: an be used for info depending on other infoImplementation: the dialogue model is not implemented yet

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 26 / 26

What have I not dis ussed?Commands: whi h they are and how to de�ne themFeedba k: how it an be in orporatedCorre tions: ommands for deleting nodes in the treeDependent types: an be used for info depending on other infoImplementation: the dialogue model is not implemented yet

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 26 / 26

What have I not dis ussed?Commands: whi h they are and how to de�ne themFeedba k: how it an be in orporatedCorre tions: ommands for deleting nodes in the treeDependent types: an be used for info depending on other infoImplementation: the dialogue model is not implemented yet

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 26 / 26

What have I not dis ussed?Commands: whi h they are and how to de�ne themFeedba k: how it an be in orporatedCorre tions: ommands for deleting nodes in the treeDependent types: an be used for info depending on other infoImplementation: the dialogue model is not implemented yet

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 26 / 26

What have I not dis ussed?Commands: whi h they are and how to de�ne themFeedba k: how it an be in orporatedCorre tions: ommands for deleting nodes in the treeDependent types: an be used for info depending on other infoImplementation: the dialogue model is not implemented yet

Peter Ljunglöf (Univ. Gothenburg) Tree-Based Dialogue Management DiaHolmia 2009 26 / 26