1 CADUI' June FUNDP Namur Defense Science & Tech. Org. Declarative interaction through interactive planners Conn V Copas Defence Science & Technology Organisation Australia Ernest A Edmonds Loughborough University of Technology Great Britain

2 CADUI' June FUNDP Namur Defense Science & Tech. Org. Presentation aims To introduce concepts of planning and declarative interaction To describe an implementation of an interactive planner –goal description languages To compare planning with HCI formalisms –model-based UIMSs –Petri nets

3 CADUI' June FUNDP Namur Defense Science & Tech. Org. Concepts of Planning - 1 Initial state: Goal state: (on C A) (on A Table) (on B Table) (on A B) (on B C) Operator definitions: operator: (move ?What ?From ?To) precondition: (clear ?What) (clear ?To) effect: (on ?What ?To) (not (on ?What ?From)) (clear ?From) (not (clear ?To)) A C BC B A

4 CADUI' June FUNDP Namur Defense Science & Tech. Org. Concepts of Planning - 2 Plan: (move C A Table) (move B Table C) (move A Table B) Planner searches (nondeteministically) for operator combinations which will achieve the goal Operators could be user-level commands A form of automatic programming

5 CADUI' June FUNDP Namur Defense Science & Tech. Org. A GIS goal “I would like to see the roads data on a white background, containing a legend in the bottom right corner and a scale-bar on top”

6 CADUI' June FUNDP Namur Defense Science & Tech. Org. A GIS command line d.mon start=x0 d.erase color=white d.rast -o map=roads d.scale at=0,0 d.frame frame=frame0 at=0,40,75,100 d.erase color=black d.legend map=roads General purpose, low-level application

7 CADUI' June FUNDP Namur Defense Science & Tech. Org. Graphical GIS user interfaces Pull-down menus reflect the command-line The interface reflects the underlying programming language Direct manipulation possibilities limited by ability to represent actions by gesture

8 CADUI' June FUNDP Namur Defense Science & Tech. Org. Declarative interaction Users describe goals; machine infers procedures Intelligent interfaces, or ‘just’ constraint satisfaction? Planners as indirect manipulation –acceptability?

9 CADUI' June FUNDP Namur Defense Science & Tech. Org. UCPOP (Penberthy & Weld 92) Public-domain planner supporting conditional effects, dynamic object universes, universal and existential quantification Proveably sound and complete –regressive –first-principles –partial-order –domain-independent –closed world assumption; instantaneous effects

10 CADUI' June FUNDP Namur Defense Science & Tech. Org. GIS domain knowledge (:operator d-rast :parameters (?container ?name ?data ?map) :precondition (and (selected ?container ?name) (data ?data) ) :effect (and (displayed-in ?container ?name map ?map) (kind map ?map two-d) (refers-to map ?map data ?data) ) (forall (?A ?B) (when (displayed-in ?container ?name ?A ?B) (not (displayed-in ?container ?name ?A ?B)))) (forall (?frame ?id ?X ?Y) (when (and (contains ?container ?name ?frame ?id) (displayed-in ?frame ?id ?X ?Y)) (not (displayed-in ?frame ?id ?X ?Y)) )) (forall (?colour) (when (background-colour ?container ?name ?colour) (not (background-colour ?container ?name ?colour)))) (forall (?frame1 ?id1 ?colour1) (when (and (contains ?container ?name ?frame1 ?id1) (background-colour ?frame1 ?id1 ?colour1)) (not (background-colour ?frame1 ?id1 ?colour1)))) )) “The d-rast command requires a currently selected container, and some data. Its effects are that a map is displayed in the container, and that, if anything is already displayed, then all contents are overwritten”

11 CADUI' June FUNDP Namur Defense Science & Tech. Org. Goal description languages problem of Lisp/Ucpop syntax problem of mastery of predicate calculus: conjunction, disjunction, negation, universal quantification lack of guidance about possible goal statements analogy with SQL: the language is declarative, demanding, and limited by its first-order nature :goal (exists (window ?x) (exists (frame ?y) (exists (scale-bar ?z) (and (background-colour ?x white) (displayed-in ?x map roads) (contains ?x ?y) (position frame ?y " ") (displayed-in ?y legend roads) (displayed-in ?x scale-bar ?z) (position scale-bar ?z "0 0") ))))

12 CADUI' June FUNDP Namur Defense Science & Tech. Org. A GIS data model Planners model state transitions, with domain structure only implicit Data model necessary for methodical UI design WINDOW DISPLAYED IN DISPLAYED IN SCALE BAR MAP position kind CONTAINSFRAME DISPLAYED IN LEGEND position background REFERS TO REFERS TO DATA kind

13 CADUI' June FUNDP Namur Defense Science & Tech. Org. A planner form-filling interface Resembles a graphical data-base interface, but with explicit quantifiers Irrelevant (to the user) whether the plan is retrieved or derived Possibility of sketching the goal?

14 CADUI' June FUNDP Namur Defense Science & Tech. Org. HCI specification Individual UIMS, CSCW and TA models? Specification causes inflexibility? Run-time generation of dynamics as a solution Formalisms: –transition networks –context-free grammars –event languages –production rules –Petri nets

15 CADUI' June FUNDP Namur Defense Science & Tech. Org. HCI specification Individual UIMS, CSCW and TA models? Specification causes inflexibility? Run-time generation of dynamics as a solution Formalisms: –transition networks –context-free grammars –event languages –production rules ATNs –Petri nets causal models high-level rules {

16 CADUI' June FUNDP Namur Defense Science & Tech. Org. Uses of causal knowledge Operators preconditions effects Knowledge base Planner - progressive - regressive + path finding algorithm Model-based UIMS (UIDE) + projection Predicate transition net + dependency analysis

17 CADUI' June FUNDP Namur Defense Science & Tech. Org. Dependency analysis Operator-1 preconditions: A effects: C,D Operator-3 preconditions: D,E effects: B,F Operator-2 preconditions: B,C effects: G

18 CADUI' June FUNDP Namur Defense Science & Tech. Org. Petri net challenges Why generate a net manually? Expressiveness –conditional effects –universal quantifiers (also a problem for model-based UIMS) Ontological clarity –inhibitor arcs? places? tokens? Scalable reachability analysis

19 CADUI' June FUNDP Namur Defense Science & Tech. Org. Conclusion –Contemporary planners are sufficiently expressive and have sufficient performance to support declarative interaction –Graphical goal description languages are possible –Planning supports constraint satisfaction, as a general solution to inflexible system dynamics Shortcomings –performance (?) –the formalist fantasy?

20 CADUI' June FUNDP Namur Defense Science & Tech. Org. Any questions?