Preliminaries

CS5540 HCI

by

Rich Riesenfeld

27 Aug 2001

What is the HCI Issue?

Is the interface the concern?

Is the matter of accomplishing some work, some set of tasks, the issue?

Are we emphasizing the wrong thing?

Doing Work View

Computer is simply the medium

Interface focus can distracting

Need to understand the characteristics of the computer/interface

Need to understand the user and human behavior

What do we already know as good interface principles?

Interesting, pleasing, attractive

Effective to use

Intuitive

Alan Kay’s children

Organized, hierarchically structured

What do we know as good interface principles? (cont)

Help functions, Search, etc

Consistent form (aka design integrity)

Automatic assistance

Completions

Spelling

What do we know as good interface principles? (cont)

Lead the user

Prompts

Indicate nature of any problem

Specific communication

What do we know as good interface principles? (cont)

Meaningful error msgs

Don’t send you elsewhere

Give useful number

Area of inadequate traditions

What do we know as good interface principles? (cont)

Multiple paths to a function

Keep it simple

Gain user’s trust.

Bottom up is probably most acceptable

Simple tasks should be simple

Our history hurts us…

Developed some poor communications habits

Resources were scare

Other priorities, historically

Our history hurts us…

Early computing:

“Compiler error”

Systems error: EM732851

Small road signs

Confusing directions

Our history hurts us…

Our history hurts us…

Korean Airlines Flight 007, with its 269 passengers and crew, had strayed off course over a Soviet missile installation in the far Pacific and was shot out of the sky

Pilot had to key in the numerical coordinates by hand corresponding to flight plan!

Our history hurts us…

How about an automatic download?

How about picking from a menu?

How about symbolic names

Our history hurts us…

Audi

Cars took off from a standing position

Driver error, claimed Audi…

Whose error was it?

Our history hurts us…

NASA

Lost a major mission over mistake in units

One group worked in SI units

One group worked in English units

Combining the results let to bad numbers

Culture

Critical Interfaces

Nuclear power plants

Interface had better be clear

Airplane cockpit controls

Computer graphics has simplified

Effect of function: Examples

Water faucets in a sink

Manual gear shift

Chords on a guitar

Interface is dictated (confused) by needed effect

Other historical examples

Books are essentially linear

Stories or communications needs might not be

Hyper-text breaks the bound with linear text

HCI is a “design problem”

Design is old subject

Well studied topic

Apply design methodologies to build better interfaces

We will look at this viewpoint

Important operational issues

Reliability

Availability

Security

Data integrity

Important Basics

Standardization across app’s

Apple first did this

Integration of packages and tools

Unix does this well

Consistency in actions, design style, terms, menus, color, fonts, etc, etc

Portability across platforms

Less true than advertised (Quicken, eg)

Palm Desktop Calendar

Palm Handheld Calendar

Important stats

Time to learn

Speed of performance

How much coffee can one drink?

Rate of errors by users

“The user is always right!”

Important stats (cont)

Retention over time

Do you have to start at square 1?

Subjective satisfaction

Do you like it (no explanation needed!)

Can you develop an attachment for it?

Dramatically different needs

Life-critical systems

Air traffic; nuclear reactors; cockpits; power utilities; emergency, military, medical, operations

Commercial

Banks, resv’s, inventory, point-of-sales (Hertz, Fedex,..), registration,..

Different needs (cont)

Home, office, entertainment

Obvious needs

Exploratory, creative, cooperative systems

Bad interface (computer or otherwise) can destroy the process

Human Diversity

Ergonomics, anthropometry

Anyone here “average?”

Physical consideration

Height, stiffness, posture, shapeness, size of working area

IPD, headsize, light sensitivity

Cognitive processes (from Engineering Abstracts)

Short-term memory

Long-term memory

(Over 40 users…)

Problem solving

Decision making

Cognitive processes (from Engineering Abstracts) (cont)

Attention and set (scope of concern)

ADHD, Ritalin population (5%)…

Search and scanning

Time perception

Perceptual and Motor Performance Factors (ibid)

Arousal and vigilance

Fatigue

Perceptual (mental) load

Knowledge of results

Monotony and boredom

Perceptual and Motor Performance Factors (ibid)

Sensory deprivation

Sleep deprivation

Anxiety and fear

Isolation

Perceptual and Motor Performance Factors (ibid)

Aging

Drugs and alcohol

Circadian rhythms

Gender Differences

Males and Females are different!

Much has been observed

Firm principles are scarce

Carl Jung’s
Personality differences

Extrovert v Introvert

Extroverts like action

Sensing v Intuition

Routine v discovering new

Carl Jung’s
Personality differences (cont)

Perceptive v judging

New situations v planning

Feeling v thinking

Sensitive v logical

Recent study result …

Multi-tasking does not work.

Ergo, one should not:

Drive a car

Talk on a mobile phone

Q: Is driving a car a single task??

Cultural and International Diversity

Characters, numerals, special characters, diacriticals

Left-to-right v right-to-left v vertical and reading

Date and time formats

Numeric and currency formats

Cultural and International Diversity (cont)

Weights and measures

Telephones and addresses

Names and titles

Mr., Ms., Mme, M., Dr.

SSNs, national Ids,

Capitalization and punctuation

Cultural and International Diversity (cont)

Sorting sequences

Icons, buttons, colors

Pluralization, grammar, spelling

Etiquette, policies, tone, formality, metaphors.

Users with Disabilities

Can truly open doors

Man with ALS who uses head to type

Doing it well requires good client model

Designer challenges

Evaluating interfaces

Understanding of a practical problem

Lucid statement of a testable hypothesis

Manipulation of small number of independent variables

Measurement of specific dependent variables

Evaluating interfaces (cont)

Careful selection and assignment of subjects

Control for bias in subjects, procedures, and materials

Application of statistical tests

Interpretation of results, refinement of theory, and guidance for experimenters

Possible research directions

Reduced anxiety of computers

Graceful evolution of systems

Specification and implementation of interaction

Direct manipulation

Possible research
directions (cont)

Input devices

Online assistance

Information exploration

End of Chapter 1


	Is the interface the concern?
	Is the matter of accomplishing some work, some set of tasks, the issue?
	Are we emphasizing the wrong thing?


	Computer is simply the medium
	Interface focus can distracting
	Need to understand the characteristics of the computer/interface
	Need to understand the user and human behavior


	Interesting, pleasing, attractive
	Effective to use
	Intuitive
		Alan Kay’s children
	Organized, hierarchically structured


	Help functions, Search, etc
	Consistent form (aka design integrity)
	Automatic assistance
		Completions
		Spelling


	Lead the user
		Prompts
		Indicate nature of any problem
		Specific communication


	Meaningful error msgs
		Don’t send you elsewhere
		Give useful number
		Area of inadequate traditions


	Multiple paths to a function
	Keep it simple
	Gain user’s trust.
	Bottom up is probably most acceptable
	Simple tasks should be simple


	Developed some poor communications habits
	Resources were scare
	Other priorities, historically


	Early computing:
		“Compiler error”
	Systems error: EM732851
	Small road signs
	Confusing directions


	Korean Airlines Flight 007, with its 269 passengers and crew, had strayed off course over a Soviet missile installation in the far Pacific and was shot out of the sky
	Pilot had to key in the numerical coordinates by hand corresponding to flight plan!


	How about an automatic download?
	How about picking from a menu?
	How about symbolic names


	Audi
		Cars took off from a standing position
		Driver error, claimed Audi…
		Whose error was it?


	NASA
		Lost a major mission over mistake in units
		One group worked in SI units
		One group worked in English units
		Combining the results let to bad numbers


	Nuclear power plants
		Interface had better be clear
	Airplane cockpit controls
		Computer graphics has simplified


	Water faucets in a sink
	Manual gear shift
	Chords on a guitar

	Interface is dictated (confused) by needed effect


	Books are essentially linear
	Stories or communications needs might not be
	Hyper-text breaks the bound with linear text


	Design is old subject
	Well studied topic
	Apply design methodologies to build better interfaces
	We will look at this viewpoint


	Standardization across app’s
		Apple first did this
	Integration of packages and tools
		Unix does this well
	Consistency in actions, design style, terms, menus, color, fonts, etc, etc
	Portability across platforms
		Less true than advertised (Quicken, eg)


	Time to learn
	Speed of performance
		How much coffee can one drink?
	Rate of errors by users
		“The user is always right!”


	Retention over time
		Do you have to start at square 1?
	Subjective satisfaction
		Do you like it (no explanation needed!)
		Can you develop an attachment for it?


	Life-critical systems
		Air traffic; nuclear reactors; cockpits; power utilities; emergency, military, medical, operations
	Commercial
		Banks, resv’s, inventory, point-of-sales (Hertz, Fedex,..), registration,..


	Home, office, entertainment
		Obvious needs
	Exploratory, creative, cooperative systems
		Bad interface (computer or otherwise) can destroy the process


	Ergonomics, anthropometry
		Anyone here “average?”
	Physical consideration
		Height, stiffness, posture, shapeness, size of working area
		IPD, headsize, light sensitivity


	Short-term memory
	Long-term memory
	(Over 40 users…)
	Problem solving
	Decision making


	Attention and set (scope of concern)
		ADHD, Ritalin population (5%)…
	Search and scanning
	Time perception


	Arousal and vigilance
	Fatigue
	Perceptual (mental) load
	Knowledge of results
	Monotony and boredom


	Sensory deprivation
	Sleep deprivation
	Anxiety and fear
	Isolation


	Males and Females are different!
	Much has been observed
	Firm principles are scarce


	Extrovert v Introvert
		Extroverts like action

	Sensing v Intuition
		Routine v discovering new


	Perceptive v judging
		New situations v planning

	Feeling v thinking
		Sensitive v logical