COMP3511 HCI Final Exam Vocabulary Flashcards
Final Examination Structure and Evaluation Framework
The evaluation format comprises multiple-choice questions to be completed within a \,-minute duration. Questions may contain more than one correct option, requiring individual assessment of every answer choice rather than discontinuing the evaluation upon identifying a single correct option. Assessment items encompass both definition-based questions and application scenarios involving visual interface screenshots.
To achieve comprehensive mastery of interaction concepts, each topic must be analyzed across five dimensions: its technical definition, visual recognition within a user interface, an example of effective implementation, an example of poor implementation, and specific design interventions for interface optimization.
Usability and User Experience Goals
Usability encompasses six distinct goals: effectiveness, efficiency, utility, safety, learnability, and memorability. Usability focuses on the pragmatic success with which a user can interact with and complete tasks within a system.
Effectiveness defines the degree to which users can accomplish their intended goals accurately and completely. For instance, an academic enrolment system demonstrates effectiveness if a student successfully registers for the exact target courses without errors.
Efficiency measures the quantity of effort and temporal resources required to complete a given task. An efficient system minimizes superfluous actions and eliminates extraneous system-driven steps that do not align naturally with the user's primary workflow.
Utility assesses whether the system provides the exact functional capabilities required by users to fulfill their objectives. Suboptimal utility arises either from functional deficiencies (missing capabilities) or feature bloat, wherein extraneous functionality degrades overall system clarity.
Safety concerns the system's capacity to avert user error and prevent operational harm. Operational mechanisms for safety include deletion confirmation prompts, comprehensive Undo capabilities, physical and visual separation of critical/destructive actions from standard workflows, and proactive safeguards against unintended data loss.
Learnability measures the ease with which novice users navigate an unfamiliar interface upon initial exposure. A highly learnable system minimizes initial cognitive confusion and reduces the temporal overhead required for a user to reach operational productivity.
Memorability denotes the ease with which a returning user retains operational proficiency after a period of non-use. While learnability governs initial system acquisition, memorability governs cognitive retrieval upon subsequent re-engagement.
User experience (UX) addresses the subjective, emotional, and psychological state generated during system interaction. Desirable user experience goals include interactions that are satisfying, enjoyable, engaging, fun, helpful, motivating, pleasurable, exciting, entertaining, challenging, stimulating, and supportive of creativity or sociability.
Undesirable user experiences include interactions that are boring, frustrating, annoying, childish, unpleasant, patronising, gimmicky, offensive, or demean user intelligence by making them feel stupid. The core conceptual boundary dictates that usability measures task performance and success, whereas user experience governs internal emotional response.
Design Principles
Design principles guide interface structure and interaction behavior to ensure effective human-computer interaction. The primary design principles include structure, affordance, visibility, feedback, consistency, constraints, and natural mapping.
Structure mandates that the interface be organized purposefully and logically. Related information, visual elements, and functional controls must be grouped together to form coherent conceptual units.
Affordance dictates that the perceived and actual physical properties of an interface element suggest its operational method. For example, a visual button must appear pressable, and a slider control must visually communicate draggability. User statements such as "I didn't know that was clickable" indicate a structural failure of affordance.
Visibility requires that necessary functions, structural information, and available operational paths remain visually exposed. Adequate visibility allows users to formulate accurate mental models of available actions and determine appropriate subsequent steps.
Feedback requires the system to provide explicit, immediate confirmation of user actions. Implementation examples include visual state changes upon pressing a button, progress indicators during asynchronous processing, or explicit status messages such as "Saved successfully." Feedback confirms system reception and execution of user input.
Consistency dictates that identical words, operational behaviors, and visual styles represent identical functions across the interface. Internal consistency ensures uniform conventions across pages or modules within the same application. External consistency maintains alignment with established industry standards across external platforms.
Constraints restrict the scope of permissible user interactions to limit operational errors. Implementation techniques include disabling contextually invalid buttons, graying out unavailable menu items, and enforcing input validation rules within forms.
Physical constraints leverage physical properties to restrict action, such as a physical key designed to fit exclusively into its corresponding lock mechanism.
Semantic constraints leverage real-world knowledge and contextual meaning to restrict options. For example, after entering the number of hotel guests, an accommodation system restricts selectable rooms strictly to those capable of accommodating that capacity.
Logical constraints utilize deductive reasoning to prevent invalid states. For example, a hotel booking system logically restricts a user from setting a check-in date that occurs chronologically after the selected check-out date.
Cultural constraints rely on arbitrary cultural conventions and shared symbols learned through societal interaction, such as utilizing the color red to signify emergency stop or system warning.
Natural mapping creates intuitive spatial or conceptual alignment between control mechanisms and their real-world outcomes. Examples include arranging kitchen stove controls in a spatial pattern matching the layout of the burners, or shaping automobile seat adjustment controls to mirror the physical geometry of the seat itself.
Nielsen's Usability Heuristics
Heuristics serve as a diagnostic framework for evaluating interface usability. Jakob Nielsen's ten usability heuristics represent fundamental evaluation criteria for system design.
Visibility of system status mandates that the system continuously inform users of ongoing operations through meaningful feedback delivered within minimal response thresholds. Implementation tools include loading spinners, progress bars, active state highlights, and explicit confirmation notifications.
Match between system and the real world requires the system to utilize natural language, familiar concepts, and real-world domain conventions rather than internal system-oriented technical jargon. Workflow structures must mirror real-world user operations.
User control and freedom dictates that users be granted explicit operational autonomy, providing clear visual mechanisms to cancel, undo, revert, or exit unwanted system states or unexpected sequences.
Consistency and standards requires adherence to standard platform conventions, visual styles, and terminology to allow users to apply existing mental models without extra cognitive friction.
Error prevention prioritizes proactive design interventions that eliminate error-prone conditions before errors occur. This includes confirmation dialogs for destructive tasks, constrained entry fields, clear interactive labels, and logical spacing between critical controls.
Recognition rather than recall leverages human perceptual strengths by rendering options, actions, and objects visible, rather than requiring users to retrieve procedural information or previous inputs from memory.
Flexibility and efficiency of use requires system adaptability for diverse expertise levels. Systems must provide accelerators, keyboard shortcuts, and customizable macros for expert users while maintaining an uncluttered interface for novices.
Aesthetic and minimalist design mandates the exclusion of irrelevant, redundant, or rarely needed information. Every extraneous visual element competes with primary functional information for user attentional capacity.
Help users recognise, diagnose and recover from errors requires error notifications to be written in plain language without cryptic technical codes, accurately describe the failure state, and provide actionable resolution steps.
Help and documentation dictates that while systems should ideally be intuitive enough to operate without instruction, necessary documentation must be easily searchable, organized around user tasks, concise, and presented as concrete step-by-step procedures.
A critical conceptual distinction exists between error prevention and error recovery: error prevention stops an error before its occurrence, whereas error recovery assists the user in resolving system failures after an error has taken place.
Visual Design Principles
While usability principles address functional task completion, visual design principles govern presentation, perception, aesthetics, and visual communication.
Clutter represents excessive visual density that increases perceptual noise, impairs visual search performance, and increases cognitive workload.
White space (negative space) refers to intentional, unpopulated areas surrounding visual elements. White space separates structural groups, lowers perceptual clutter, enhances organizational hierarchy, and promotes visual balance. Extensive white space is a intentional design tool rather than a functional deficiency.
Alignment establishes consistent visual axes across interface elements. Proper alignment reduces visual clutter, supports rapid eye scanning, establishes visual orientation, and promotes aesthetic harmony.
Symmetry distributes visual weight evenly across a central axis, instilling a sense of stability, formal balance, and predictable structure.
Asymmetry achieves visual equilibrium without mirror-image duplication. Asymmetrical designs balance elements through contrasting variations in scale, position, color, and visual weight.
Gestalt Principles of Perceptual Organization
Gestalt principles describe the psychological mechanisms by which human visual perception organizes discrete visual elements into unified groups or structures.
Proximity dictates that objects positioned in close spatial proximity are perceived as a cohesive, related group. For example, positioning a text label adjacent to an input field causes the perceptual system to group them as a single functional unit.
Similarity states that visual elements sharing visual characteristics—such as color, shape, scale, or typographic style—are perceived as belonging to the same category or performing the same function.
Focal point asserts that elements exhibiting strong visual contrast relative to surrounding items capture immediate attentional priority. Designers establish focal points using contrasting colors, enlarged dimensions, unique geometry, or strategic positioning.
Closure describes the cognitive tendency to mentally close gaps in incomplete visual forms, perceiving complete, unified figures even when visual information is partially omitted.
Colour and Menu Design
Color in interface design serves to direct user attention, categorize spatial relationships, and signal system status. Color must be applied deliberately and sparingly to ensure seamless integration with structural elements.
Standard color harmony categories utilized in visual design include analogous colors (adjacent hues on the color wheel), complementary colors (opposing hues on the color wheel), triadic colors (three evenly spaced hues forming an equilateral triangle), and natural palettes derived from nature.
Effective menu design requires grouping logically related commands, assigning unambiguous operational titles, restricting vertical hierarchy depth, maintaining uniform phrasing, physically isolating destructive operations from routine options, and visually graying out currently unavailable commands.
The inclusion of an ellipsis () appended to a menu command explicitly indicates that execution will not occur immediately, but will instead open a dialog requiring additional user input.
Card sorting is an empirical user research technique used to establish intuitive information architectures and content hierarchies. Participants sort domain topics into structural categories, enabling designers to discover common cognitive patterns across sessions.
Accessibility and Universal Access
Universal access demands that digital services and systems offer equivalent operational utility to all users regardless of functional disability, demographic background, ethnicity, or socioeconomic status.
Accessibility involves designing interfaces that are perceivable, operable, and understandable across varying user abilities, while providing structural compatibility with external assistive technologies.
The World Wide Web Consortium (W3C) is the governing standards body responsible for web protocols, including the Web Content Accessibility Guidelines (WCAG 2.2).
Assistive technologies include screen readers, screen magnification applications, refreshable Braille displays, speech recognition systems, alternative mice and keyboards, eye-gaze tracking input systems, head pointers, sip-and-puff switches, specialized gamepads, and brain-computer interfaces.
Screen readers parse structured visual data and convert on-screen text into synthesized speech or output to refreshable Braille hardware. Non-text graphical assets must include meaningful text alternatives (alt text), as screen readers cannot interpret raw raster images.
Color contrast evaluates the luminance differential between foreground elements (such as body text) and background surfaces. Maximizing contrast enhances legibility. Pure black text on a pure white background provides the maximum achievable contrast ratio of .
Prevalent accessibility barriers include insufficient luminance contrast ratios, relying exclusively on color to convey critical status information, micro-scale typography, inadequate touch target dimensions, absent alt text for visual media, non-navigable keyboard structures, and missing visual keyboard focus indicators.
Cross-Screen, Adaptive, and Orientation Design
Cross-screen design encompasses creating multi-device user experiences across mobile phones, tablets, desktop workstations, and wearable technology while preserving usability, visual consistency, and cross-device task continuity.
Layout adaptation involves reconfiguring interface components to fit target screens, such as transforming a multi-column desktop sidebar into a mobile bottom navigation bar.
Content adaptation involves contextually hiding, prioritizing, or summarizing content based on display real estate limitations.
Interaction adaptation alters input mechanisms to align with device hardware, such as translating desktop hover states into mobile tap-to-reveal gestures.
Functional adaptation modulates accessible system feature sets according to device capabilities and user contexts.
Contextual adaptation dynamically reconfigures the user interface according to real-world operational environments, such as simplifying an auto-navigation display into high-contrast, voice-driven interfaces during driving.
Fluid orientation design dynamically adjusts layout geometry to match device rotation seamlessly.
Extended orientation design appends or removes structural interface components based on aspect ratio changes.
Complementary orientation design uses device rotation to uncover supplementary contextual data.
Continuous orientation design assigns device rotation as an explicit trigger to access a secondary sub-interface.
For touch-based interaction interfaces, critical functional controls must reside within the ergonomic sweep of the user's thumb (the thumb zone). Interactive target areas must maintain minimum dimensions of , with smaller interactive targets separated by expanded spatial buffers.
User-Centred Design Process
User-Centred Design (UCD) is an iterative development methodology prioritized around end-user requirements and feedback loops throughout the lifecycle.
The UCD workflow integrates creative ideation, establishing the Product Description Statement, identifying internal/external stakeholders, data gathering, data analysis, persona and scenario development, functional and non-functional requirements specification, requirement validation, low-fidelity and high-fidelity prototyping, usability test execution, issue logging, design reviews, and continuous iteration.
The iterative core of UCD requires that empirical user research directly informs initial design, design concepts undergo rigorous testing, testing exposes usability defects, and these findings drive subsequent design updates.
A Product Description Statement explicitly details the functional parameters of the application and articulates how the proposed system fulfills user goals.
Data Gathering Methodologies
Primary empirical data collection methods in HCI include structured/semi-structured interviews, focus groups, survey questionnaires, direct field observation, and indirect observation.
Interviewing requires aligning questions with study goals, maintaining consistency, eliminating leading questions, omitting domain jargon, avoiding multi-part questions, recording accurate session transcripts, and ensuring participant comfort. Formal written informed consent is required prior to interview sessions.
Focus groups comprise moderated discussions involving approximately to participants selected to represent target demographic groups. A qualified facilitator directs the agenda while exploring spontaneous qualitative insights.
Questionnaires support open-ended and closed-ended items, enabling rapid distribution across expansive sample populations. However, questionnaires lack qualitative flexibility and are vulnerable to sampling bias and low response rates.
Direct observation in the field records user interactions within authentic context environments. Ethnography requires immersive qualitative research within the operational culture of the target population.
Think-aloud protocol is a direct observation methodology where participants continuously verbalize their cognitive processes, rationale, and frustrations while interacting with a system. Facilitators must maintain neutrality, providing non-leading prompts such as "What are you thinking about now?" or "Describe what is on screen."
Personas and Scenarios
Personas are archetypal, evidence-based fictional characters constructed from qualitative and quantitative empirical research to represent distinct target user segments.
Persona profiles typically integrate character names, ages, demographic profiles, representative photographic assets, primary goals, emotional drivers, and online behavior patterns.
A context scenario details user objectives, internal motivations, and real-world task contexts. Context scenarios are strictly user-focused rather than system-focused, non-technological, and omit granular interface actions like button presses. Context scenarios are structured around five core questions: who, what, when, why, and where.
A task scenario specifies an operational instruction given to a study participant during a usability testing session. Context scenarios belong strictly to the early design and requirements phase, whereas task scenarios belong to the usability evaluation phase.
Requirements Engineering and Prototyping
Functional requirements explicitly define specific operations, computations, features, and behaviors the system must execute.
Non-functional requirements specify operational qualities, performance criteria, constraints, and systemic characteristics, including usability thresholds and accessibility compliance standards.
Prototypes represent iterative visual models constructed based on project objectives, user research data, personas, scenarios, and information architectures.
Low-fidelity prototypes are rough, low-cost representations (such as paper sketches and structural wireframes) designed to facilitate rapid modification and early concept validation.
High-fidelity prototypes closely mirror the visual design, interactive states, and behavior of the final software, providing realistic operational fidelity for late-stage usability testing.
Design patterns represent reusable spatial and functional solutions to common interface problems. An accordion consists of vertically stacked, collapsible panels used to organize links within tight layout boundaries. A wizard guides users through complex sequential workflows by breaking tasks into structured steps.
Usability Testing Frameworks
Usability testing occurs across prototyping, system development, and post-deployment phases, transitioning from early low-fidelity testing to late high-fidelity evaluations.
The usability evaluation cycle consists of three phases: session planning, test administration, and data analysis, documentation, and reporting.
A usability test plan must define evaluation metrics, outline domain scenarios, formalize data collection protocols, establish participant selection criteria, and assign explicit evaluator roles.
A standardized usability testing procedure follows a fixed execution sequence: participant introduction, signed informed consent execution, pre-test baseline questionnaire administration, standardized script instructions read by the facilitator, task scenario execution, post-test satisfaction questionnaire administration, and participant debriefing.
Quantitative measurement parameters include task execution duration, total error count, click counts, and task success rate percentages.
Qualitative evaluation parameters capture user comments, observed behavioral confusion, think-aloud verbal transcripts, and subjective ratings of perceived ease of use.
An issues table organizes identified usability defects by logging the defect description, severity rating, and associated violated design principle. For example, a user's inability to locate a sign-in control reflects failures in structure and visibility; misinterpreting icon meanings reflects a failure in the match between system and the real world; and failing to recognize an image asset as interactive indicates an affordance defect.
Quantitative Performance Models
Performance models allow theoretical prediction of human execution performance without empirical user testing, facilitating analytical comparison across alternative interface layouts.
The Keystroke-Level Model (KLM) predicts the time required for an expert user to complete a routine task on a software interface by summing execution times assigned to specific low-level operators:
Keystroke or button press.
Pointing to a target on a display screen using a mouse.
Homing hands between keyboard and pointing device.
Mental preparation or cognitive retrieval.
Mouse button press or release action.
System processing delay.
Fitts' Law predicts the total time required to move a pointing device to a target display area based on target distance and width:
In this equation, represents Movement Time, represents the physical Distance to the target, represents the target Width along the axis of motion, and constants and represent empirically derived empirical regression parameters. The fundamental rule dictates that larger and closer targets enable faster selection, whereas smaller and more distant targets increase task duration.
Research Ethics in Human-Computer Interaction
Ethical guidelines dictate researcher responsibilities to safeguard participant well-being, autonomy, and data privacy.
Informed consent requires participants to fully comprehend study objectives, procedural tasks, potential risks, and data logging methods before voluntarily agreeing to participate.
Voluntary participation ensures that individuals retain the right to decline participation or withdraw from testing at any phase without incurring penalty, financial loss, or negative bias.
Privacy and confidentiality require the protection of participant data. Identifiable markers must be redacted, replaced with randomized subject codes, stored on secure servers, and restricted to authorized research staff.
Researchers are obligated to minimize potential physical or psychological harm, including stress, social embarrassment, anxiety, and simulator sickness induced by Virtual Reality (VR).
Ethical administration mandates equitable participant treatment, prohibiting discrimination, exploitation, coercive pressure, or assigning personal blame to participants for operational errors during usability testing. Evaluators must maintain the core principle: the system is being tested, not the participant.
If research methodology necessitates experimental deception, participants must undergo debriefing immediately following session completion, receiving full disclosure of study parameters and the option to redact their recorded data.
Cognitive Load Theory
Cognitive Load Theory (CLT) is based on the architecture of human memory, specifically the limited capacity of working memory, which processes active conscious thoughts.
Human working memory is constrained to processing approximately distinct information elements simultaneously when handling un-chunked information.
Intrinsic cognitive load is caused by the inherent structural complexity of the domain material itself. It depends on element interactivity and the learner's prior knowledge schemas.
Extraneous cognitive load stems from poor instructional design, confusing interface presentation, visual clutter, redundant actions, and inefficient navigation. Design interventions aim to reduce extraneous load.
Germane cognitive load involves the constructive mental effort devoted to synthesizing, processing, and automating cognitive schemas. Interfaces should minimize extraneous load to free capacity for germane processing.
Cognitive Load Effects and Instructional Strategies
The split-attention effect occurs when users must mentally integrate multiple physically or temporally separated sources of related information. Examples include separating a graphical diagram from its textual legend, requiring users to retain facts across different screens, or forcing toggling between software and external documentation. This effect is mitigated by physically integrating related text directly into visual diagrams and synchronizing complementary audio-visual channels.
The redundancy effect occurs when users are forced to process identical or non-functional duplicate information. Processing redundant visual assets or non-essential text consumes limited working memory capacity without providing additional utility.
The modality effect demonstrates that cognitive capacity can be expanded by distributing information processing across independent sensory channels, using visual and auditory pathways simultaneously.
The transient information effect occurs when information disappears before the user completes cognitive processing, such as transient audio clips or fast-disappearing animations. Complex information should be segmented or presented in persistent written formats.
Signalling involves using visual cues—such as arrows, structural highlighting, or bold typography—to direct user attention immediately to critical task elements.
Training wheels involves hiding or disabling complex functionalities for novice users. This reduces the number of elements competing for working memory, allowing novices to master core operations before exposure to advanced tools.
The worked example effect demonstrates that novice users acquire skill faster when provided with explicit step-by-step solved exemplars rather than relying on unguided trial-and-error problem-solving.
Reducing search reduces extraneous load by integrating contextually related information, restricting information volume per screen, maintaining layout consistency, highlighting priority content, and providing predictable navigation structures.
Cognitive Load in Usability Heuristics
Usability heuristics directly reduce extraneous cognitive load:
Visibility of system status eliminates unnecessary cognitive search by keeping the user continuously aware of internal system states.
Match between system and real world aligns interface constructs with existing real-world cognitive schemas, reducing interpretation effort.
User control and freedom provides clear recovery paths, reducing the mental stress and cognitive load associated with making errors.
Consistency reinforces mental models, allowing users to predict control locations and system responses.
Error prevention preserves cognitive resources by proactively shielding users from complex error-recovery procedures.
Flexibility and efficiency provides expert shortcuts, lowering physical and mental steps for advanced users without confusing novices.
Clear error recovery provides explicit actionable instructions, assisting users in updating incorrect mental models.
Aesthetic and minimalist design eliminates extraneous visual noise, preserving working memory for core tasks.
Cognitive Architectures of Novices and Experts
Novices possess limited domain-specific knowledge and lack organized mental structures, forcing them to rely on surface visual characteristics and explicit step-by-step guidance.
Experts possess extensive domain-specific knowledge organized into automated cognitive schemas. A schema is a domain-specific knowledge structure that allows multiple discrete pieces of information to be categorized and processed as a single cognitive unit.
Declarative knowledge consists of explicit facts, definitions, and conceptual information.
Procedural knowledge consists of operational knowledge regarding how to execute physical or cognitive tasks.
Experts recognize visual patterns, chunk complex information, retain domain details, utilize shortcuts, and analyze underlying structural relationships.
The expertise reversal effect occurs when instructional features designed to assist novices (such as worked examples or step-by-step prompts) become redundant extraneous load for experts. Interfaces manage this by offering adaptive modes, providing simplified guided views for novices while exposing detailed, shortcut-driven control layouts for experts.
Internationalisation and Localisation
Internationalisation is the foundational engineering process of designing and architecting an application codebase to accommodate diverse cultural, language, and regional requirements without structural source code refactoring.
Localisation is the subsequent process of adapting an internationalised application to conform to specific regional, linguistic, and cultural environments. In short: internationalisation prepares the system, while localisation adapts it.
Localization requires modifying alphabets, linguistic translation, text directionality, layout alignment, visual metaphors, iconography, image content, cultural color symbolism, date/time formats, numeric structures, currency units, and systems of measurement.
Direct word-for-word translation is insufficient for full localisation; software must account for visual space shifts, local conventions, cultural idioms, visual iconography, and overall layout adaptivity. Internationalisation considerations must be embedded from project inception.
Gamification Systems
Gamification is the practice of embedding game design mechanics and structural elements into non-game software applications to enhance user engagement.
Game-inspired design applies basic playful elements to non-game contexts; serious games are fully developed games built explicitly for educational or non-entertainment purposes; and gamification overlays structural game loops onto standard task workflows.
Structural gamification applies reward frameworks (such as points or badges) to encourage engagement without altering the core content. Content gamification alters the target content itself to make it inherently game-like.
Core game mechanics include narrative arcs, interactive controls, clear goals, progressive challenge scaling, time constraints, tracking systems, real-time feedback loops, and reward systems.
Reward categories encompass points, virtual currencies, achievement badges, and level progressions.
Reward delivery structures include fixed-action rewards, sudden rewards, random rewards, rolling rewards, prize pacing schedules, and social recognition rewards.
Input, Output, and Sensing Technologies
Mobile hardware integration expands user interface input boundaries through hardware sensors:
Accelerometers measure multi-axis device acceleration, velocity, and tilt orientation, enabling spatial motion interactions such as controlling objects by tilting the physical device.
Global Positioning System (GPS) sensors provide spatial location data, enabling context-aware services.
Cameras capture visual inputs, enable optical scanning, and superimpose digital objects for augmented reality.
Microphones enable speech recognition and acoustic input monitoring.
Multitouch displays process multi-point gesture inputs, supporting pinch, zoom, swipe, and multi-finger interactions.
Heart-rate monitors track physiological metrics, enabling health monitoring applications.
Stylus inputs enable high-precision spatial point entry, handwriting recognition, and freehand drawing.
Virtual Reality, Augmented Reality, and the Metaverse
The metaverse is an interconnected network of persistent, three-dimensional virtual environments focused on real-time social interaction, characterized primarily by perceptual immersion.
Virtual Reality (VR) completely replaces the user's physical visual field with a computer-generated synthetic environment. Core VR capabilities include simulating fully synthetic environments and supporting interactive 3D gaming.
Augmented Reality (AR) superimposes context-aware digital assets and graphics directly onto a live view of the physical world.
Key design principles for VR and AR include maximizing immersion, maintaining intuitive 3D spatial interactions, delivering real-time feedback, preserving minimalist visual layouts, ensuring text legibility, managing spatial depth, guiding user attention, using visual signalling, and prioritizing ergonomic comfort.
Comfort management in VR requires reducing factors that induce motion sickness, such as latency and visual-vestibular mismatch. Recommended mitigation techniques include maintaining high frame rates, supporting smooth visual rendering, enabling user-driven teleportation, and utilizing snap-turning mechanics rather than continuous rotation.
Social Computing and Human-Centred AI
Social computing leverages digital technologies to support interpersonal interactions, social connectivity, and group collaboration. Key concepts include social presence, mediated communication, digital identity management, feedback loops, and cultural norms.
Collaborative computing provides shared tools to support group problem-solving and decision-making across physical and temporal boundaries, such as Google Docs and Wikipedia.
Crowdsourcing (crowd computing) distributes complex task units across large online populations, combining human intelligence with computational aggregation.
Human-Centred Artificial Intelligence focuses on designing AI systems that augment, support, and adapt to human needs rather than replacing human agency.
Narrow AI is designed to solve specific, tightly defined operational tasks within a single domain.
General AI refers to hypothetical artificial intelligence possessing cross-domain human-level reasoning and cognitive flexibility.
Intelligent User Interfaces combine machine learning, automated reasoning, plan recognition, and perception to adapt to user goals dynamically.
Core HCI Distinctions and Reference Summaries
Usability vs. User Experience: Usability evaluates task success, performance, accuracy, and operational efficiency. User Experience evaluates internal feelings, emotional responses, and psychological satisfaction.
Visibility vs. Feedback: Visibility ensures operational controls and system states remain visually accessible. Feedback provides confirmation following a user action.
Affordance vs. Natural Mapping: Affordance indicates how an individual object can be operated based on its visual appearance. Natural mapping aligns control arrangements with their real-world spatial outcomes.
Error Prevention vs. Error Recovery: Error prevention eliminates error-prone conditions before mistakes occur. Error recovery provides mechanisms and guidance to fix errors after they occur.
Recognition vs. Recall: Recognition relies on identifying visible options. Recall requires retrieving information from memory.
Context Scenario vs. Task Scenario: Context scenarios describe high-level user goals, contexts, and workflows during the early design phase without technology-specific details. Task scenarios specify concrete operational instructions given to participants during usability testing.
Functional vs. Non-Functional Requirements: Functional requirements specify what specific tasks the software must execute. Non-functional requirements specify operational qualities, usability targets, and system performance attributes.
Internationalisation vs. Localisation: Internationalisation is the baseline architectural preparation of software to support multiple locales. Localisation is the subsequent adaptation of that software to a specific target culture and language.
Virtual Reality vs. Augmented Reality: Virtual Reality replaces physical reality with a synthetic digital environment. Augmented Reality overlays digital visual content onto the real-world environment.
Novices vs. Experts: Novices possess limited domain knowledge and lack organized mental schemas, requiring guided assistance. Experts possess extensive, automated domain schemas that enable rapid pattern recognition and shortcut utilization.
Intrinsic vs. Extraneous vs. Germane Cognitive Load: Intrinsic load stems from inherent domain complexity. Extraneous load is caused by poor presentation and unnecessary mental processing. Germane load is the mental effort dedicated to schema acquisition and learning.
Split-Attention vs. Redundancy Effect: Split-attention occurs when integrated processing requires mentally combining physically separated information sources. Redundancy occurs when processing duplicated or non-essential information wastes working memory capacity.
Low-Fidelity vs. High-Fidelity Prototypes: Low-fidelity prototypes are cheap, rough representations used for rapid early iteration. High-fidelity prototypes are detailed, interactive representations used for realistic late-stage testing.