Lecture 2a: Foundations of human-computer interaction CSCI102 - Introduction to Information Technology B ITCS905 - Fundamentals of Information Technology

Overview  Motivation  Why care about people?  Contexts for HCI  Tools  Web hypermedia

Overview  Human performance models  Perception  Movement  Cognition  Introduction to usability testing

Motivation: Why Care About People?  Human - computer interaction (HCI)  The study of the ways that people use computers  Practice of making computers easier for people to use  Is that possible?  Yes  It happens when people who design computers and software keep in mind that they are designing for other people

Motivation: Why Care About People?  It happens when those designers understand that people use computers to do work  They don't care whether the work gets done by a computer or by magic  They just want to get the work done  The same is true of games  People want to play games  They want the illusion that the game is real

Motivation: Why Care About People?  It happens when designers  Realize that the work people do while using computers is work intended for other people to use  Accept that they must first understand the work that people do  Before they can even begin to design a computer or a program that will do that work

Motivation: Why Care About People?  It happens when designers  Learn that it is much more effective for the computer to adapt to the needs of the person, than for the person to adapt to the needs of the computer  And the companies they work for, understand that a failure of usability is every bit as important as any other software or hardware failure or error  Accept that people who use products are the best people to evaluate whether those products are easy to use, or whether they do what they are supposed to do

Motivation: Why Care About People?  It is the designer's job to understand and meet those expectations, not to dictate them  Products that are easy to use  do not come from a box  do not come from toolkits  do not come from standards  do not provide Function  They provide possibilities

Motivation: Why Care About People?  Products that are easy to use come from people who care enough to make those products easy for other people to use  "Easy to use" is not a cliché or a marketing slogan  It is not achieved as often as it is claimed  It is hard work  It is a way of life  It is a discipline, and that discipline is called "HCI"

Motivation: Why Care About People?  If you are a programmer, the task analysis and prototyping that are an integral part of this approach to development will give you concrete goals for the design of your software  You won't have to guess what users want, because they will already have told you

Motivation: Why Care About People?  If you are a technical writer, working with a task-oriented product means that you spend less effort explaining how to integrate functions into tasks, and more time helping users integrate the software into their work and their lives  If you are a marketer, a task-oriented product will help you sell

Motivation: Why Care About People?  If you are a development manager, using a task-oriented approach to building highly usable products will lower your support costs and improve customer satisfaction  If you are building a web site, the fundamentals of the HCI approach--task analysis and user-centered design--will help you focus on delivering your message to your readers

Contexts for HCI  Context definition  The part of a text or statement that surrounds a particular word or passage and determines its meaning  The circumstances in which an event occurs; A setting

Contexts for HCI – Tools  Typical HCI deliverables include  Flowcharts, sitemaps, conceptual diagrams, site hierarchies, storyboards, prototypes, requirements & narratives, blueprints, screen schematics  Tools to deliver these include  Flowcharts, MindMaps, task analysis, PowerPoint, cognitive walkthroughs, requirement specification, procedural manuals

Contexts for HCI - Web Hypermedia  The Internet provides us with another context within with to view human- computer interaction  Vannevar Bush first wrote of the device he called the memex early in the 1930s

Contexts for HCI - Web Hypermedia  The memex is  "A device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility"  It resembled a desk with two pen-ready touch screen monitors and a scanner surface  The ability to navigate the enormous data store was seen as a more important development than the futuristic hardware

Human Performance Models  The Human Model Processor – from last week  The model can be divided into three interacting subsystems: 1. The perceptual system 2. The cognitive system 3. The motor system  Each with its own set of memories and processors

Human Performance Models – Perception  Visual  Auditory  Touch

Human Performance Models– cognition  Cognitive models represent users of interactive systems  Hierarchical models represent a user's task and goal structure  Linguistic models represent the user-system grammar  Physical and device models represent human motor skills  Cognitive architectures underlie all of these cognitive models.

Human Performance Models – movement  Time taken to respond to stimulus: reaction time + movement time  Movement time  dependent on age, fitness etc.  Reaction time  dependent on stimulus type:  visual - 200ms  auditory ms  pain - 700ms

Introduction to Usability Testing  User requirements modelling is concerned with establishing user needs  Socio-technical models represent both human and technical requirements  Soft systems methodology takes a broader view of human and organizational issues  Participatory design incorporates the user directly into the design process

Introduction to Usability Testing  Cognitive models represent users of interactive systems  Hierarchical models represent a user's task and goal structure  Linguistic models represent the user-system grammar  Physical and device models represent human motor skill  Cognitive architectures underlie all of these cognitive models