IT 223 (Part 4)

• The purpose of interaction is to accomplish a goal within an application domain.
• Interaction refers to the engagement between a user and a system within a specific context, aimed at achieving a certain goal.
• The purpose of interaction is to accomplish a goal within an application domain.
• Goal - desired output
• Domain - area of expertise
• Tasks – operations to be performed to manipulate the domain
• Task analysis – identification of the problem space for the user in terms of domain, goals, intentions, and tasks
• System – refers to the computer-based system
• Core language – language of the computer-based system
• Task language – User’s language
• User – refers to the person
• Interactions take place between the user and the system
• Interface must translate between the user and the system
• In interaction, translation can fail at a number of points
• The Abowd and Beale Framework emphasizes the cyclical and interactive nature of HCI
• The Abowd and Beale Framework model helps designers and researchers understand the different elements involved in HCI and how they interact with each other, which is crucial for creating user-friendly and effective computer systems.
• Frameworks are meant to be means of judging overall usability of an interactive system
• Controller-display relationships, or mappings, refer to how user actions (through a controller) affect changes on a display or system.
• A well-designed CD relationship should be natural, seamless, efficient, and intuitive, meaning that the user can predict and understand the system's response to their actions.
• Types of mappings

  ● Spatial Mapping

  ● Gain and Transfer Functions

  ● Latency

  ● Property Sensed and Order of Control:
• Spatial Mapping: Refers to how physical movements correspond to movements in the system's interface.
• Gain and Transfer Functions: Describe the relationship between the input (controller movement) and output (response magnitude).
• Latency: Is the delay between user action and system response.
• Property Sensed and Order of Control: Deals with the type of input the system can detect (like touch, pressure, or position) and how it controls the system's response.
• Spatial Mapping: For example, dragging a finger across a touchpad moves the cursor on the screen in the same direction, creating an intuitive connection between user action and system response.
• Gain and Transfer Functions: In a video game, for instance, the speed of an on-screen character may increase more rapidly than the speed at which the joystick is pushed (non-linear gain), requiring the user to adapt to the control sensitivity.
• In real-time applications like online gaming, high latency can disrupt the experience, as there is a noticeable delay between user commands and on-screen actions, affecting performance and user satisfaction.
• The order of control in human-computer interaction refers to how the property sensed by the controller influences the system's response.
• Order of control determines whether the sensed property directly controls the position or velocity of the display or system.
• Isotonic Control: In this order of control, the property sensed (such as pressure) directly controls the position of the display or system.
• Isometric Control: Here, the property sensed controls the velocity or speed of the display's movement, rather than its position.
• Isotonic Control: For example, pressing harder on a touchscreen zooms in more on a map, directly correlating pressure to the display's scale.
• Isometric Control: An example is a joystick where pushing it harder makes the controlled object move faster, regardless of its final position.
• Natural vs. learned relationships in human-computer interaction refer to the distinction between interactions that are instinctive and those that users need to learn over time.
• Natural Relationships: These are interactions that align closely with users' existing knowledge and behaviors, making them intuitive and easy to understand without prior instruction.
• Natural Relationships: For example, scrolling through a web page by swiping up or down on a touch screen feels natural because it mimics the physical action of turning a page in a book.
• Learned Relationships: Require users to acquire new knowledge or skills to understand how an interaction works.
• Learned Relationships: This often involves familiarizing oneself with the system's interface and learning the mappings between user actions and system responses.
• Learned Relationships: An example is learning keyboard shortcuts to perform tasks efficiently in software applications.
• Mental Models: These are like mental blueprints we create based on our past experiences to understand how things work.