CEN3722 Human Computer Interaction Overview of HCI Dr. Ron Eaglin

Objectives What is HCI ? Understand the importance of HCI Understand User Centered Design Understanding Users (psychology, needs, tasks) Involvement of users in design process Understand goals of HCI Usability

Objectives HCI Design Methodology Understand Users and Tasks Create prototypes (mockups) Evaluation (usability/acceptance/testing) DesignPrototype EvaluateRepeat

What is HCI? Design Tasks Users Technology Context

Context of HCI Design Social Issues Target Users Organizational Issues Cost Issues and Budget Platform

Importance Pervasiveness of Technology Reliance of Users on Technology Usability Safe Usable Functional

What is Usability? Learnable: Ability to learn system quickly (minimal training) Recall: Remember how to use between sessions Productive: Tasks are performed quickly and efficiently Accurate: Prevents errors or assists users in correcting errors Satisfaction: User has good experience and high confidence of success

What is User Centered Design? Design is done from the User Perspective User and customer are not the same person You work directly with the target users Defines the system and what it will do Iteration and feedback are part of process

Know Thy User (design golden rule) Physical abilities of the users Cognitive abilities of the users Recall ability Learning ability Background Culture of the User Culture of the Organization Experience of the User Users jobs (tasks/motivations)

Example Memorize this directory structure c:\human computer interaction\user centered design\prototyping\task analysis\goms analysis\

Example Recall is difficult Recognition is easier

Software Design Team Software Developers Graphics Designers Software Testers Psychologists/Human Factors Technical Writers Marketing specialist And……

Software Design Team And….. Users

Design Cycle (traditional example) Requirements Gathering User Analysis Task Analysis Design Prototype Evaluate Programming Deliver

UCSD Design Process 1. Business Analysis 2. Planning and Design 3. Usability Design 4. Evaluation 5. Introduce System

Prototyping More iterations = better results Create mock-ups Sketches Whiteboard Users Fidelity – Level of detail

Evaluate Use models to evaluate Usability (example GOMS) Models can predict human performance Select from alternative designs before prototype builds Pre-prototype not 100% predictive (catching user errors) Discount usability techniques User prototype testing with users

Discount Usability Techniques Heuristic evaluation Design violations documented and rated Cognitive walk-though to evaluate learnability Asks “why” in addition to “how”

User Testing Expensive Requires Real users Real tasks Prototype Real users perform real tasks Real users provide best feedback for design

Summary – you should be able to: What is HCI and why is it important? What is user centered design? What are the aspects of usability? Describe user based design methodologies