Lecture 2a: Foundations of human-computer interaction

CSCI102 - Introduction to Information Technology B

ITCS905 - Fundamentals of Information Technology

OverviewMotivation

Why care about people?Contexts for HCI

Tools Web hypermedia

OverviewHuman 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 HCIContext 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 HypermediaThe 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 system2. The cognitive system3. The motor system

Each with its own set of memories and processors

Human Performance Models – PerceptionVisualAuditoryTouch

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 - 150 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