[HCI] Usefulness - Mental Model

Goals of the Study

1. What is USFULNESS
   Whether using digital systems helps people effectively achieve their goals.
2. What needs to be understood?
   • 시스템의 목적
   • 시스템의 구조
   • 시스템의 작동
3. Mental model
   What people have in mind about the valuel, function & structure of a digital system
4. Can be divided by three depending on the level of abstraction
   • Structural model
   • Functional model
   • Value model
     • Functional value
     • Playful value
     • Personal value
     • Social value
5. Can be divided by three depending on perspective
   • User model
   • Developer model
   • System image

Usefulness

1. Problem space
   • Initial state
   • Goal state
   • Operator
   • Condition
2. Design space
   • all product and service alternatives의 집합
   • Mental model : Model of the system drawn in a user's mind, user perspective

Mental Model

• 사람마다 다른 knowledge structure
• Dynamic
  상황에 대해 자율적으로 수정과 업데이트 가능, target들은 사람의 머리에 가상적으로 작동
• Incomplete and sometimes conflicting
  개인 인지 능력에 영향을 받는다. 사람에 의존되기 때문에 정확 혹은 부정확한 model이 만들어진다.

Mental model의 역할

• Describing phenomenon
  • 현재의 시스템 상황을 설명
• Explaining reason
  • 시스템 작동과 관련된 인과관계 설명
• Predictin future
  • 시스템이 어떻게 작동될지 예측

User vs Developer

Norman's Action Cycle

1. What do I want to accomplish?(goal)

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2. What are the alternative actions sequences?(plan)
3. What action can I do now?(specify(
4. How do I do it?(perform)

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5. What happened?(perceive)
6. What does it mean?(interpret)
7. Is it okay? Have I accomplished my goal?(compare)

Mental Model and Behavioral Theory

• Gulf of execution(실행차)
• Gulf of evaluation(평가차)