Understanding Computer System Interactions

Interaction with Computer Systems

• Interaction involves the exchange of information and commands between a user and a computer.
• The interaction spans from basic command-line inputs to virtual reality experiences.
• Good interaction design enhances system usability, making it easier for users to achieve their goals.
• Effective interaction increases user satisfaction and productivity.
• Varying interaction methods increase a system's accessibility to accommodate different user abilities and preferences.

Models of Interaction

• Interaction models illustrate how users and systems interact, bridging gaps and potentially highlighting issues.
• Norman's Execution-Evaluation Cycle describes the process where users form goals, plan actions, execute them, and then evaluate outcomes.
• Norman's Execution-Evaluation cycle emphasizes the importance of aligning system responses with user expectations, and informs where communication breakdowns occur.
• Extended models, building on Norman's cycle. incorporate context or feedback mechanisms.
• Both types of models focus on user goals and actions.

Terms of Interaction

• Domain refers to the area of work under study (e.g., graphic design).
• Goal refers to what the user wants to achieve (e.g., create a solid red triangle).
• Task refers to how the user goes about doing it, in terms of operations or actions, such as selecting a fill tool and clicking over a triangle.

Norman's Model of Interaction

• Users formulate a plan of action and execute it at the computer interface.
• Users observe the interface to evaluate results and determine further actions once the plan is executed.
• The interactive cycle has with two phases; execution, and evaluation
• The phases are subdivided into seven stages/steps.
• Step 1: Establish a Goal
• Step 2: Form an Intention.
• Step 3: Specify the Action Sequence.
• Step 4: Execute the Action.
• Step 5: Perceive the System State.
• Step 6: Interpret the System State.
• Step 7: Evaluate the System State in respect to the Goals and intentions.
• Execution Phase; Form the goal, is where the user decides what they want to achieve.
• Execution Phase; Forming the intention, is where he user plans the actions needed to achieve the goal.
• Execution Phase; Specifying the action, is where the user determines the specific steps required.
• Execution Phase; Executing the action, is where the user performs the actions through the computer interface.
• Evaluation Phase; Perceiving the state of the system, is where the user observes the system's response to their actions.
• Evaluation Phase; Interpreting the state of the system, is where the user understands the system's response in relation to their goal.
• Evaluation Phase; Evaluating the outcome, is where the user compares the system's response with the goal to determine if it has been achieved.

Execution/Evaluation Loop Breakdown

• Goal --> Execution --> System --> Evaluation
• The user first establishes a goal, then formulates an intention, and specifies actions at the interface.
• Next, the user executes an action, perceives the system state, and interprets the system state.
• The user evaluates the system state with respect to goal.

Interaction Framework: Components

• System: Core functionalities and operations of the interactive system with its specific language.
• User: The individual interacting with the system, using a task language to express goals.
• Input: User's information or commands, formatted and transmitted using its own language.
• Output: The system's responses or feedback to the user's input.
• Input and Output form the Interface, and is channel through which communication occurs.
• The framework facilitates the analysis of communication processes and outcomes in interactive systems.

Interaction Framework: Aspects

• Users convert intentions into actions at the interface, causing changes in system state.
• These changes are reflected in the output display and interpreted by the user.
• The interaction framework identifies all major components involved in interaction and allows comparative assessment of systems.
• The interaction framework is an abstraction and not specifically restricted to hardware.

Ergonomics

• Ergonomics focuses on the physical aspects of human-system interaction, it is also known as Human Factors.
• Ergonomics examines how control designs, physical environments, and display layouts affect user experience.
• The goal of ergonomics is to optimize elements based on human psychology and system constraints to enhance the user experience.
• Key issues include the arrangement of controls and displays, the design of physical environments and the impact of color on interactions.
• There can an overlap with Human-Computer Interaction (HCI).
• Ergonomics focuses on physical interactions and environmental factors for efficient, comfortable, and safe user-system interactions.
• Examples include arrangement of controls and displays, grouped by function or frequency of use.
• Seating arrangements adapt to all user sizes.
• Tackling health issues; physical position, temperature, humidity, lighting, and noise.
• Use of color, the use of red for warning, green for okay, with consideration for color-blindness.

Interface Styles

• Interface style selection affects interaction between users and computers.
• Common interface styles include the command line interface, menus, natural language, question/answer and query dialog, form-fills and spreadsheets, WIMP, point and click , and three-dimensional interfaces.
• Command Line Interface: Way of expressing instructions to the computer directly, typical example: Unix System commands.
• GUI Menus: Is an option displayed on the screen, relying on recognition so names should be meaningful and can be selected by numbers, letters, arrow keys, mouse etc.
• Natural language: Everyday language used by humans and has key characteristics such as flexibility, ambiguity, context dependency, is productive, complex and universal.
• Query interfaces: Is a question/answer style interface, suitable for novice users.

WIMP Interface

• WIMP (windows, icons, menus, pointers) is the default interface for most interactive computer systems, such as PCs and desktop workstations.
• Many common environments for interactive computing are examples of the WIMP interface style, often simply called windowing systems.
• Examples of WIMP interfaces include Microsoft Windows for IBM PC compatibles, MacOS for Apple Macintosh compatibles and various X Windows-based systems for UNIX.

WIMP Interface: Elements

• windows, icons, menus, pointers.
• buttons, toolbars, palettes, dialog boxes

WIMP: Windows, Scrollbars and Title Bars

• Windows are areas of the screen that behave as if they were independent, and can contain text or graphics , can be moved or resized can overlap each other.
• Scrollbars allow the user to move the contents of the window up and down or from side to side
• Title bars describe the name of the window.

WIMP: Icons

• In computing, icons are small graphical symbols that represent various system elements, they depict minimized windows, and clicking an icon restores the window to full size.
• Icons have several functions: Space saving, task management, system component representation.
• Iconifying is reducing a window to its icon.

WIMP: Pointers

• WIMP relies on pointing and selecting things by use of mouse, trackpad, joystick, trackball, cursor keys or keyboard shortcuts.
• Different cursor shapes distinguish modes and tell the user about system activity.

GUI Menus

• Menus offer users a selection of operations or services in both windowing and non-windowing environments.
• Key characteristics of menus include their structured presentation of operations as an ordered list.
• Menu commands should be named in a clear, meaningful manner to provide informative cues to users
• They is enhance user interaction by offering a straightforward way to access and execute system functionalities efficiently.

Type of menus

• Main Menu is also known as the primary or top-level menu, appearing at the top, and containing essential categories like File, Edit, View, and Help.
• Context Menu which is also called a right-click or popup menu, appears when the user right-clicks on an object.
• Dropdown Menu appears when the user clicks on a dropdown arrow.
• Toolbar Menu, also known as a toolbar dropdown or overflow menu, is accessed from an icon on a toolbar.

GUI: Buttons

• Buttons are individual and isolated regions within a display that can be selected to invoke an action
• Two kinds of buttons exist Radio buttons and check boxes.
• Radio buttons are a set of mutually exclusive choices.
• Check boxes are set of non-exclusive choices.

GUI: Toolbars

• Toolbars, small icon-based buttons located at the top or side of a window, offers quick access to frequently used functions
• There are two kinds of tool bars, Fixed Toolbars and customizable Toolbars.
• Fixed Toolbars feature a set of predetermined functions.
• Customizable Toolbars allow users to add, remove, or rearrange buttons to fit their workflow.

GUI: Palettes

• Palettes are visual tools in software interfaces showing available modes and the current active mode.
• Palettes' customization allows users to create or modify palettes from menus or toolbars , and are often displayed like tear-off menus.

GUI: Dialogue boxes

• Dialogue boxes are essential information windows in user interfaces to alert users to important information like errors or warnings.
• Dialogue boxes can initiate specific subdialogs between the user and system.

Interactivity and Computing

• Involves the dynamic exchange of information and actions between users and computer systems, enhancing engagement and responsiveness in digital environments.
• Key Aspects, Engagement, Feedback, User-Centered design and Multi-Modal Interaction.
• Interactivity is essential in applications like websites, software interfaces, games, educational tools, and simulations, significantly enhancing functionality and usability.

Context of Interaction

• Context of interaction is the specific circumstances and environment where users engage with digital systems
• The context of interaction includes Environment, User Goals, System Capabilities, User Characteristics
• Context of interaction also includes Contextual Variables, Feedback Mechanisms
• Understanding contextual elements is essential for designing effective, user-friendly interfaces.