Kang Chang Ryong

6 분 소요

Dialogue Notations and Design

  • Dialogue Notations
    • Diagrammatic(그림으로 그릴 수 있는)
      • State transition networks, JSD (Jackson Structured Design) diagrams, Flow charts(플로우차트)
    • Textual(텍스트 형식)
      • Formal grammars, Production rules, CSP (Communication Sequential Process)
  • Dialogue linked to
    • The semantics of the system – what it does
    • The presentation of the system – how it looks
  • Formal descriptions can be analyzed
    • For inconsistent actions
    • For difficult to reverse actions
    • For missing actions
    • For potential miskeying errors(엉뚱한 거 잘못눌러서 생기는 error)

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What is dialogue?

  • Conversation between two or more parties
  • Usually cooperative
  • In user interfacesimage-20221010155431809
    • Refers to the structure of the interaction
    • Syntactic level of human–computer ‘conversation’
  • Levels
    • Lexical (어휘)– shape of icons, actual keys pressed
    • Syntactic – order of inputs and outputs(어떤 순서로 눌러야 dialogue가 나오는지)
    • Semantic – effect on internal application/data


Structured Human Dialogue

  • Human-computer dialogue is very constrained
  • Some human-human dialogue is formal too …
    • 사람과 사람의 대화도 fix 되어 있는 경우가 있음

image-20221010155444821

(marriage dialogue)


Lessons about Dialogue

  • Wedding service
    • Sort of script for three parties
    • Specifies order
    • Some contributions fixed – “I do”
      • 몇몇은 고정된 말
    • Others variable – “do you man’s name …”
      • 사람 이름은 변수로 작용(사람마다 이름을 다르게 불러야 하기 때문에)
    • Instructions for ring concurrent with saying words “with this ring …”
  • If you say these words, are you married?
    • Only if in the right place, with marriage licence
    • Syntax is not semantics
      • syntax가 지켜진다고 해도 semantic이 맞지 않으면 동작하지 않는 것


… and more(예외 사항)

  • What if woman says “I don’t”?
  • Real dialogues often have alternatives:
    • image-20221010155528104
    • The process of the trial depends on the defendants response
  • Focus on normative responses
    • Doesn’t cope with judge saying “off with her head”
      • 머리를 날려버려와 같은 말을 할 수 있는 것도 아니고…
    • Or in computer dialogue user standing on keyboard!


Dialogue Design Notations

  • Dialogue gets buried in the program
    • 프로그램 안 쪽에 깊이 있을 것임
  • In a big system can we:
    • Analyse the dialogue:
      • e.g. Can the user always get to see current shopping basket
    • Change platforms
      • e.g. migration from Windows to Mac
    • Dialogue notations helps us to
      • Analyse systems
      • Separate lexical from semantic (어휘와 의미 분류)
  • … and before the system is built
    • Notations help us understand proposed designs


Graphical Notations

  • State-Transition Nets (STN)
  • Petri Nets
  • State Charts
  • Flow Charts
  • Jackson Structured Design (JSD) Diagrams


State Transition Networks (STN)

  • Circles - states
  • Arcs – actions (output) / events (input)

image-20221010155630038

rubber band - 고무줄


State Transition Networks - Events

  • Arc labels a bit cramped because:
  • Notation is ‘state heavy’
  • The events require most detail

image-20221010155649582


State Transition Networks - States

  • Labels in circles a bit uninformative:
    • States are hard to name
    • But easier to visualise

image-20221010155707130

state가 unique하지 않고 state가 10개쯤 나오는 경우가 생기면 이름 짓기가 어려움

  • 비슷한 종류의 작업이 있어도 이름을 다르게 해야하기 때문


Example: Bottle Dispense STN

image

H state: history


Hierarchical STNs

  • Managing complex dialogues
  • Named sub-dialogues

image-20221010155731957


Strengths and Limitations

  • Strengths
    • Easy to interpret
    • Allows choice and iteration to be modelled.
  • Limitations
    • Concurrent dialogue(왜 문제? - 아래에서 나옴)
    • Unusual actions (esc, help)


Concurrent dialogues - ISimple dialogue box

image-20221010155756039


Concurrent dialogues - IIThree toggles - Individual STNs

image-20221010155816898


Concurrent dialogues - III Bold and Italic combined

image-20221010155829177


Concurrent dialogues - IV All together - Combinatorial explosion

image-20221010155838527


Escapes

  • ‘Back’ in web, escape/cancel keys
    • Similar behavior everywhere
    • End up with spaghetti of identical behaviors
  • Try to avoid this
  • e.g. on high level diagram
    • ‘Normal’ exit foreach submenu
    • Separateescape arc active‘everywhere’ in submenu

image


Help menus

  • Similar problems
    • Nearly the same everywhere
    • But return to same point in dialogue
    • Could specify on STN … but very messy
    • Usually best added at a ‘meta’ level

image-20221010155927059


Petri Nets

  • One of the oldest notations in computing!image-20221010155950985
    • A simple model of active behavior
    • Provide a graphical explanation for easy understanding.
  • Four elements of Flow graph:
    • Places: Used to symbolize passive elements of the reactive system. A place is represented by a circle.
    • Transitions: Used to symbolize active elements of the reactive system. Transitions are represented by squares/rectangles.
    • Arc: Used to represent causal relations. Arc is represented by arrows.
    • Token: Sit on places (current state). Subject to change. Tokens are represented by small filled circles.
      • 토큰이 네트워크 안을 돌아다님
    • 토큰을 주고 받는 형태로 일을 한다.(토큰이 있는 곳이 현재 state)


Role of a Token

  • A physical object, for example a product, a part, a drug, a person
  • An information object, for example a message, a signal, a report
  • A collection of objects, for example a truck with products, a warehouse with parts, or an address file
  • An indicator of a state, for example the indicator of the state in which a process is, or the state of an object
  • An indicator of a condition: the presence of a token indicates whether a certain condition is fulfilled
  • Several tokens allowed: Concurrent dialogue states


Role of a Place

  • A type of communication medium, like a telephone line, a middleman, or a communication network
  • A buffer: for example, a depot, a queue or a post bin
  • A geographical location, like a place in a warehouse, office or hospital
  • A possible state or state condition: for example, the floor where an elevator is, or the condition that a specialist is available


Role of a Transition

  • An event (e.g., starting an operation, the switching of a traffic light from red to green)
  • A transformation of an object, like adapting a product, updating a database, or updating a document
  • A transport of an object: for example, transporting goods, or sending a file


Construction Rules

  • Connections are directed(방향성이 존재)
  • No connections between two places or two transitions is allowed
    • place와 place, transition과 transition끼리 연결될 수는 없음
    • 반드시 transition을 거쳐서 place로 가야됨.
  • Places may hold zero or more tokens
  • A transition is enabled if each of its input places contains at least one token

image-20221010160101228

leave transition

각각에 하나씩 하나 이상의 토큰이 있어야 동작

enter: photographer가 프리이고 customer가 before로 갈 때


Petri Net example

image-20221010160112486

bold on에서 bold off로 토큰이 넘어감.


Example: In a Restaurant

image-20221010160120866

waiter가 free여야 customers가 order를 받을 수 있음


Example: In a Restaurant (Scenarios)

  • Scenario 1:
    • Start
      • -> Waiter takes order from customer 1
      • -> serves customer 1
      • -> takes order from customer 2
      • -> serves customer 2 => End
  • Scenario 2:
    • Start
      • -> Waiter takes order from customer 1
      • -> takes order from customer 2
      • -> serves customer 2
      • -> serves customer 1 => End

시나리오 1이 안되면 customer 2는 매우 오래 기다려야 할 것이므로 불만이 생길 것이다.


Example: In a Restaurant (Scenario 1)

image-20221010160226413


Example: In a Restaurant (Scenario 2)

image-20221010160235640

둘 중에 결정하는 transition은 없음

두 개가 한꺼번에 만족 되면 그 중 하나의 transition으로만 이동해야 함.

  • 어느쪽으로 갈지는 여기서는 결정 하지 않음


State Charts

  • Harel’s state charts are a form of STN, to address problems.
  • Hierarchy is used within a single diagram to show alternative and concurrent states.
  • Used in UML (Unified Modelling Language)
  • Extension to STN
  • Example Problem: A television control panel.
    • The controller has five buttons “on”, “off”, “mute”, “sel” and “reset”
    • The TV is either ON or in STANDBY mode
    • When On, user can control the sound with the Mute button and the channel with the Sel Button.


State Charts (A television control panel)

  • Extension to STN
    • Hierarchy
    • Two concurrent sub-nets
    • Escapes
      • OFF always active
    • History
      • Link marked H goes back to last state on re-entering subdialogue

image-20221010160313667

H: history ; 이전 상태

reset 버튼 누르면 default 값( Initial state)으로 간다.


Three Toggles

  • Toggles now tidy to represent in State Charts

image-20221010160325130


Flowcharts

  • Familiar toprogrammers
  • Boxes
    • Process/Event
    • Not state
  • Use for dialogue (not internal algorithm)

image-20221010160345767


It works!

  • Formal notations – too much work?
  • COBOL transaction processing
    • Event-driven – like web interfaces
    • Programs structure ≠ dialogue structure
      • 그냥 다음 프로세스가 무엇인지를 알려주는 구조
  • Used dialogue flow charts
    • Discuss with clients
    • Transform to code
    • Systematic testing
    • 1000% productivity gain
  • Formalism saves time!!


JSD Diagrams

  • Jackson Structured Design (JSD)
  • For tree structured dialogues
    • Sequence determined left to right
    • Less expressive
    • Greater clarity

image-20221010160427780

  • *은 iteration 표시

  • 동그라미는 option으로 여러 선택지 중 하나를 수행(left에서 right으로 가는 것이 아니라)

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