Human-Computer Interaction (HCI) Principles

• Human-Computer Interaction (HCI) focuses on the design, evaluation, and implementation of interactive computing systems for human use, along with the study of related phenomena.
• User-centered design prioritizes designing systems around the needs, preferences, and limitations of end users through iterative feedback and testing.
• Affordance refers to an object's attributes that make its use clear to people.
• Conceptual models in HCI provide users with a mental framework to understand and predict an interactive system's behavior.

Interface Metaphors

• These include the desktop metaphor (files, folders, trash bin), shopping cart (e-commerce), and calendar (scheduling apps).

Interaction Design Activities

• Establishing requirements involves the needs of the user
• Developing alternatives to meet user needs
• Prototyping in order to test designs
• Evaluation of how effective the design meets requirements

Human Memory

• Recognition is identifying something when it is presented
• Recall is retrieving information from memory without cues

Usability Testing

• Usability testing evaluates how effectively users can use a system to achieve their goals and identify usability issues.
• Observing real users as they interact with a system to complete specific tasks is a common usability testing method.

Prototypes

• Prototypes are used to explore ideas, gather feedback, and test functionality early and iteratively before full development.
• Heuristic evaluation in HCI is a usability inspection method where experts review an interface against established usability principles.
• Usability heuristics are guidelines used to evaluate the usability of an interface such as visibility of system status and error prevention.
• Mental models in HCI represent a user’s understanding of how a system works and help guide their interactions.

Gulfs of Execution and Evaluation

• The gulf of execution is the gap between a user’s intention and the system’s means to carry it out.
• The gulf of evaluation is the gap between the system’s output and the user’s ability to interpret it.
• Persuasive technology example: A fitness app uses notifications and achievements to encourage regular exercise.
• User research in HCI is for understanding user behaviors, needs, and motivations through observation and analysis for better design decisions.

User Research Methods

• Methods include interviews, surveys, and diary studies.
• A persona in HCI is a fictional character representing a target user group, based on real user data.
• User stories in HCI describe user needs and interactions from their perspective, helping prioritize features and design decisions.
• Card-based prototyping in HCI is a low-fidelity technique using paper cards to represent UI elements or screens, useful for brainstorming and testing flow.
• According to Johnson and Henderson (2002), a conceptual model in interaction design is primarily concerned with describing what users can do with a system and how they can do it.

Conceptual Model Components

• The concept provides an overview of the idea to understand
• The relationship to the concepts and how it relates to the user's experience
• Mappings of how the interface translates to the user
• Metaphors to support understanding of how the relationship work

Interface Metaphors

• Interface metaphors help users understand and interact with unfamiliar systems by drawing on familiar real-world concepts.
• Core concepts in HCI include usability, interaction, feedback, visibility, constraints, consistency, and user control.

Practical Issues in User-Centered Design

• Issues include cost, time, access to users, skill levels, context of use, technical constraints.
• Persuasive design is a design approach aimed at changing user behavior or attitudes through the interface, often used in health, education, or sustainability.

Prototyping Tools

• Card-based design: Using physical or digital cards to represent UI elements for quick prototyping and layout testing.
• Storyboard: Creating visual narratives to illustrate user interactions and experiences with a product.
• User experience map: Visually outlining the steps a user takes to achieve a goal within a product or service.

HCI Design Process

• The HCI design process is iterative and starts with user requirements analysis, prototyping, and feedback.

Requirements in HCI

• Functional requirements: What the system should do.
• Non-functional requirements: Performance, security.
• User requirements: Needs and goals of the users.
• Environmental/contextual requirements: Physical, social, technical environments.