Chapter 1: Introduction to Human Computer Interaction (HCI)
What is HCI?
Definition
- HCI is the study of people and computing and the way they influence each other.
- It involves three core components: Human + Computer + Interaction.
- Previously referred to as man-machine interaction (MMI).
Causes
Goals / Objectives
- Not explicitly listed under this subtopic (see “The Goals of HCI” subtopic for details)
Importance
- Central to designing systems that are safe, easy to learn, and easy to use.
- Usability is the main concept in HCI, highlighting its foundational role in system design.
Procedures
Benefits
- Not specified in notes (see “Benefits” under “Usability”)
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
Examples
- Cockpit design during World War II (as a historical reference to early HCI concerns)
The Goals of HCI
Definition
Causes
Goals / Objectives
- Increase individual and organizational productivity
- Improve safety and reduce health hazards
- Reduce costs associated with the development of user interfaces
Importance
Procedures
Benefits
- Not specified in notes (see “Benefits” under “Usability”)
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
Examples
Evolution of Computing and User Interfaces
Definition
Causes
- Shift from expensive, expert-operated computing resources to cheap, widely accessible systems operated by non-experts.
Goals / Objectives
Importance
- Shows how user interface paradigms evolved in response to changes in technology accessibility and user demographics.
Procedures
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
- Enabled broader adoption of computing by non-experts through more intuitive interfaces.
Examples
- 1950s/60s: Computing resources were expensive; operated by highly trained professionals
- 1970s: Introduction of personal computers and Command Line Interface (CLI)
- 1980s: Emergence of Graphical User Interface (GUI)
- Xerox Star: First commercial mouse-based GUI
- 1984: Macintosh with GUI
- 1987: Windows 1.0 and 2.0
- 1990s/2000s: Computing resources became cheap; operated by non-computer experts
- Present–future: Ubiquitous/Pervasive Computing
User Interface (UI)
Definition
- The part of a product/system/software that the user sees, hears, and touches.
Causes
Goals / Objectives
Importance
- Serves as the primary point of contact between the user and the system; directly affects usability and user experience.
Procedures
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
Examples
- Standard PC UI components: screen, keyboard, mouse, speakers
- Other systems:
- Microphone (for voice input)
- Buttons (e.g., ON/OFF, CANCEL on printers, remote controllers)
- Lights (e.g., on modems, ATMs, air-conditioners)
- Hand-tracking glove (detects finger movements)
- Eye tracker (traces where the user is looking)
Human (in HCI Context)
Definition
- The user (human) is the person whom computer systems are designed to assist.
Causes
- Humans are limited in their capacity to process information, which influences design decisions.
Goals / Objectives
Importance
- Understanding human capabilities and limitations is essential for effective system design.
Procedures
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
- Human cognitive limits have important implications for interface design (e.g., avoiding information overload).
Examples
- Not specified in notes (though referenced as “more details in coming chapter”)
Interaction
Definition
- The dynamic relationship between users and systems, mediated through the user interface.
Causes
Goals / Objectives
Importance
- Central to HCI as it encompasses how users engage with systems.
Procedures
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
Examples
- Key related concepts mentioned: User Interface (UI), Usability, User Experience (UX)
Usability
Definition
- The effectiveness, efficiency, and satisfaction with which specified users achieve specified goals in particular environments (ISO 9241-11:2018).
- A quality attribute that assesses how easy user interfaces are to use.
Causes
- Poor design choices that ignore user needs, tasks, or contexts.
Goals / Objectives
- Make systems safe, easy to learn, and easy to use.
Importance
- Usability is the main concept in HCI; critical for user adoption, safety, and productivity.
Procedures
- Measured through three core dimensions:
- Effectiveness: completeness and accuracy of goal achievement
- Efficiency: resources (e.g., time, effort) used relative to results
- Satisfaction: user’s physical, cognitive, and emotional responses
Benefits
- To developers:
- Minimize cost of customer support
- Reduce time needed for training
- Build good reputation
- To users:
- Increased productivity
- Reduced learning time
- Reduced errors
- Reduced stress
Advantages & Disadvantages
- Advantages:
- Supports user-centered design
- Improves overall system quality and perception
- Disadvantages:
Impact / Effect
- Poor usability can:
- Cause users to make more errors
- Create unnecessary anxiety and inconvenience
- Decrease user productivity
- Make products difficult to use and learn
- Lead to perception of low quality and value
Examples
- Systems with high usability are easy to use; those with low usability give users a “nightmare.”
Effectiveness (Usability Dimension)
Definition
- The completeness and accuracy with which users achieve specified goals.
Causes
Goals / Objectives
- Ensure users can successfully complete their intended tasks correctly.
Importance
- Determines whether the system delivers the desired output accurately.
Procedures
- Evaluated by checking:
- Whether user goals were met successfully
- Whether all work is correct
- Whether desired output matches actual output
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
- Answers the question: “Can users use the system to do the work they need to do?”
Examples
Efficiency (Usability Dimension)
Definition
- The resources used (e.g., time, human effort, costs, materials) in relation to the results achieved.
Causes
Goals / Objectives
- Enable users to complete tasks quickly once they’ve learned the system.
Importance
- Complements effectiveness by focusing on performance speed and resource use.
Procedures
- Assessed by measuring how quickly experienced users can perform tasks.
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
- Answers questions like:
- “Can experienced users be productive using the system?”
- “Once users have learned the design, how quickly can they perform tasks?”
Examples
Satisfaction (Usability Dimension)
Definition
- The user’s physical, cognitive, and emotional responses resulting from system use that meet their needs and expectations.
Causes
Goals / Objectives
- Ensure the system is comfortable and acceptable to users and others affected by its use.
Importance
- Reflects subjective user experience, influencing long-term adoption and perception.
Procedures
- Evaluated based on user comfort, emotional response, and perceived acceptability.
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
- Answers the question: “How pleasant is it to use the design?”
Examples
User Experience (UX)
Definition
- A person’s perceptions and responses resulting from the use and/or anticipated use of a product, system, or service (ISO 9241-210:2010).
Causes
Goals / Objectives
Importance
- Extends beyond usability to include emotional and experiential qualities of interaction.
Procedures
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
Examples
- Positive UX qualities include:
- Enjoyable
- Fun
- Entertaining
- Helpful
- Motivating
- Aesthetic
- Rewarding
- Emotionally fulfilling
- Informative
- Reference example: Gojek redesign case study (linked in notes)
Usability + UX
Definition
- Combined focus on functional performance (usability) and emotional/user-centered qualities (UX).
Causes
Goals / Objectives
Importance
- Together, they ensure systems are not only usable but also engaging and satisfying.
Procedures
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
Examples
Effect of Poor UI Design / Usability Problems
Definition
- Negative outcomes resulting from interfaces that are difficult to use or poorly designed.
Causes
- Design that ignores user needs, tasks, or contexts; lack of user testing.
Goals / Objectives
- Not applicable (this describes a problem, not a goal)
Importance
- Highlights why usability must be prioritized in design.
Procedures
Benefits
Advantages & Disadvantages
- Advantages:
- Disadvantages:
- Not specified in notes (but effects listed under “Impact”)
Impact / Effect
- Causes users to make more errors
- Creates unnecessary anxiety and inconvenience
- Decreases user productivity
- Makes the product difficult to use and learn
- Leads to perception of low quality and value
Examples
- Not specified in notes (though implied through general descriptions)
How to Design a Good UI with Good Usability
Definition
Causes
Goals / Objectives
- Provide knowledge to design good UIs for products/systems/software.
- Create systems that are easy to use (high usability).
Importance
- Essential for user adoption, satisfaction, and system success.
Procedures
- Focus on users and their tasks (user-centered design)
- Build a little (prototype), test a little (usability test)
- Iterate until a good design is achieved
Benefits
- People like systems/applications that are easy to use.
- High usability leads to better user experiences.
Advantages & Disadvantages
- Advantages:
- Disadvantages:
Impact / Effect
- Avoids “nightmare” user experiences associated with low usability.
Examples
Disciplines Contributing to HCI
Definition
- Academic and practical fields that inform HCI design and research.
Causes
- Complexity of interactive systems requires multidisciplinary insight.
Goals / Objectives
- Integrate diverse knowledge to understand:
- The computer system
- The user and their tasks
- The environment in which tasks occur
Importance
- “It is not possible to design effective interactive systems from one discipline in isolation” — Alan Dix
Procedures
- Draw on expertise from multiple domains during design and evaluation.
Benefits
- Enables holistic, human-centered system design.
Advantages & Disadvantages
- Advantages:
- Comprehensive understanding of technical and human factors
- Disadvantages:
Impact / Effect
- Leads to more effective, usable, and contextually appropriate systems.
Examples
- Computer Science:
- Study of software construction
- Provides knowledge about technology capabilities and limitations
- Cognitive Psychology:
- Study of how information is processed and represented in the mind
- Provides knowledge about user capabilities and limitations
- Ergonomics/Human Factors:
- Study of humans in relation to their working environment
- Informs tool and environment design to suit users
- Social and Organizational Psychology:
- Contributes understanding of group dynamics, culture, and organizational contexts
HCI and Software Development
Definition
- Integration of HCI principles into the software development lifecycle.
Causes
- Traditional software development often neglects user needs until late stages.
Goals / Objectives
- Shift from system-centered to user-centered development.
Importance
- Ensures that usability and user experience are built into the product from the start.
Procedures
- Traditional (Waterfall) Approach:
- Sequential stages: requirements → design → coding → testing → deployment
- Driven by functional processing requirements
- Delivers what designers think users want
- HCI Framework:
- Focus on user needs
- Analyze user tasks to support functionality
- Build prototypes
- Conduct early usability testing and evaluation with users
- Iterate until good design is achieved
Benefits
- Early detection of usability issues
- Higher user satisfaction and system effectiveness
Advantages & Disadvantages
- Advantages:
- HCI framework enables iterative, user-centered refinement
- Disadvantages:
- Waterfall model may deliver systems that don’t meet real user needs
Impact / Effect
- The essential difference: Iteration — HCI emphasizes continuous user feedback and redesign.
Examples
- Waterfall model: rigid, linear progression
- HCI framework: flexible, cyclical, user-involved
PACT Analysis
Definition
- A framework for understanding the context before beginning UI design by analyzing People, Activities, Contexts, and Technologies.
Causes
- Need to assess current situations and identify opportunities for improvement in system design.
Goals / Objectives
- Identify and understand the current situation to inform better design decisions.
Importance
- Ensures design is grounded in real-world user and environmental factors.
Procedures
- Analyze four dimensions:
- People: sociology, culture, biology, language, psychology, etc.
- Activity & Context: interactions within a “community of practice” (e.g., business organization of information)
- Technologies: selection of appropriate software and hardware
Benefits
- Prevents design assumptions by grounding decisions in user and context realities.
Advantages & Disadvantages
- Advantages:
- Holistic view of design context
- Disadvantages:
Impact / Effect
- Leads to more appropriate, usable, and effective system designs.
Examples
- Designing a train ticket machine:
- People: physical traits (age, height, weight), psychology (memory, mental models), usage level (expert vs. novice)
- Activities: timing (when/frequency), complexity, safety-critical nature, content type (information/media)
- Context: physical environment, social context (culture/language)
- Technology: input (touch screen, mouse), output (monitor, speaker)