1. Dialogue Notations and Design IACT 403 IACT 931 CSCI 324 Human Computer Interface Lecturer:Gene Awyzio Room:3.117 Phone:4221 4090 Email:gene@uow.edu.au

2. Overview zDialogue Notations yDiagrammatic ystate transition networks yJSD diagrams yFlow charts yTextual yformal grammars yproduction rules yCSP

3. Overview zDialogue Analysis ySemantics and dialogue yProperties of dialogue yPresentation and lexical issues zExample yDigital watch

4. State transition networks zCircles - states zarcs - actions/events zArc labels a bit cramped because: ynotation is `state heavy‘ ythe events require most detail

5. Hierarchical STNs zmanaging complex dialogues znamed sub-dialogues

6. Hierarchical STNs

7. Flowcharts zfamiliar to programmers zboxes - process/event not state

8. JSD diagrams zfor tree structured dialogues yless expressive ygreater clarity * oooo

9. Concurrent dialogues (i)  Text Style zThree toggles - individual STNs No Bold Bold Click over bold No Italic Italic Click over italic No Under- line Under- line Click over Underline

10. Concurrent dialogues (ii)  Text Style zbold and italic combined

11. Concurrent dialogues (iii) zcombinatorial explosion yn toggles y2n states

12. Textual - Grammars zRegular expressions ysel-line click click* dble-click zCompare with JSD ysame computational model ydifferent notation yBNF xexpr ::= empty | atom expr | `(' expr `)' expr xmore powerful than regular exp. or STNs xStill NO concurrent dialogue

13. Production rules if condition then action zGood for concurrency zEvent based production rules ySel-line  first yC-point first  rest yC-point rest  rest yD-point rest  zBad for sequence zBad at state!

14. Propositional Production System zState based zAttributes: yMouse: {mouse-off, select-line, click-point, double- click} yLine-state: {menu, _first, rest} zRules (feedback not shown): yselect-line  mouse-off first yclick-point first  mouse-off rest yclick-point rest  mouse-off ydouble-click rest  mouse-off menu zBad at events!

15. CSP and process algebras zused in Alexander's SPI, and Agent notation zgood for sequential dialogues yBold-tog = select-bold?  bold-on  select-bold?  bold-off  Bold-tog yItalic-tog = … yUnder-tog = … zand concurrent dialogue yDialogue-box = Bold-tog || Italic-tog ||Under-tog zbut causality unclear

16. Dialogue Notations | Summary zDiagrammatic ySTN yJSD yFlow charts zTextual ygrammars yproduction rules yCSP

17. Dialogue Notations | Summary zIssues yevent base vs. state based ypower vs. clarity ymodel vs. notation ysequential vs. concurrent

18. Semantics - Alexander's SPI (i) zTwo part specification: yEventCSP - pure dialogue order yEventISL - target dependent semantics zCentralised dialogue description zTolerable syntactic/semantic trade-off

19. Semantics - Alexander's SPI (ii) zEventCSP yLogin = login-mess  get-name  Passwd yPasswd = passwd-mess  ( invalid  Login [] valid  Session) zEventISL yevent: login-mess xprompt: true xout: "login:" event: get-name yuses: input xset: user-id = input event: valid yuses: input, user-id, passwd-db xwhen: passwd-id = passwd-db(user-id)

20. Semantics - code zEvent loop for word processor zDistributed dialogue description zTerrible syntactic/semantic trade-off

21. Semantics - code switch ( ev.type ) { case button_down: if ( in_text ( ev.pos ) ) { mode = selecting; mark_selection_start(ev.pos); }... case button_up: if ( in_text ( ev.pos ) && mode == selecting ) { mode = normal; mark_selection_end(ev.pos); }... case mouse_move: if ( mode == selecting ) { extend_selection(ev.pos); }... } /* end of switch */

22. Action properties zcompleteness ymissed arcs yunforeseen circumstances zdeterminism yseveral arcs for one action ydeliberate: application decision yaccident: production rules, ynested escapes zconsistency ysame action, same effect? ymodes and visibility

23. Checking properties (i) zCompleteness: ydouble-click in circle states? zReversibility: yto reverse select `line' from graphics Menu yclick - double click - select `graphics' y(3 actions) yN.B. not undo

24. State properties zreachability ycan you get anywhere from anywhere? yand how easily zreversibility ycan you get to the previous state? ybut NOT undo zdangerous states ysome states you don't want to get to

25. Dangerous states (i) zWord processor: two modes and exit yF1 - changes mode yF2 - exit (and save) yEsc - no mode change zbut … yEsc resets autosave

26. Dangerous states (ii) zexit with/without save  dangerous states zduplicate states - semantic distinction zF1-F2 - exit with save zF1-Esc-F2 - exit no save

27. Lexical issues zvisibility ydifferentiate modes and states yannotations to dialogue zstyle ycommand - verb noun ymouse-based - noun verb

28. Lexical issues zlayout ydangerous states (previous slide) yold keyboard - OK ynew keyboard - disaster

29. Dialogue Analysis - Summary zSemantics and dialogue yattaching semantics ydistributed/centralised dialogue description ymaximising syntactic description zProperties of dialogue yaction properties: completeness, determinism, consistency ystate properties: reachability, reversibility, dangerous states zPresentation and lexical issues yvisibility ystyle ylayout zN.B. not independent of dialogue

30. Digital watch - User's instructions zlimited interface - 3 buttons zbutton A moves between main modes zdangerous states yguarded by two second hold zcompleteness ydistinguish depress A from release A ywhat do they do in all modes?

31. Digital watch - Designer's instructions zand that's only one button!