Lecture 2a: Foundations of human-computer interaction

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

2. Overview • Motivation • Why care about people? • Contexts for HCI • Tools • Web hypermedia

3. Overview • Human performance models • Perception • Movement • Cognition • Introduction to usability testing

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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"

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

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

18. Human Performance Models – Perception • Visual • Auditory • Touch

19. 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.

20. 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 - 150 ms • pain - 700ms

21. 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

22. 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