topic 1_ hci knowledge

8/8/2019 Topic 1_ HCI Knowledge

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MTI 6033 Text-and Speech based HCI

By : Pn. Nur Saadah Binti Fathil

Topic 1 :Foundation of HCI


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Definition of HCI

Human-computer interaction is a disciplineconcerned with the design, evaluation and

implementation of interactive computingsystems forhuman use and with the study of majorphenomena surrounding them.

(ACM SIGCHI, 1992, p.6)

Human-Computer Interaction (HCI) is a study oftherelationships which exist between humanusers and the computersystems they use in theperformance of their various tasks.

(Christine Faulkner : 2001)


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Human-ComputerInteraction (HCI) is about

designing computer systems that support people

so that they can carry out theiractivitiesproductively and safely.

(Preece, 2002)

HCI in the context oforganizational work is to

understand and shape the way people interact withcomputers: the processes they engage in, the

resources they use and the impact they accomplish.(Teeni,Carey & Zhang, 2007)

Definition of HCI


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The Nature of HCI

From ACM SIGCHI Curricula for Human-Computer Interaction


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HCI & OtherDiscipline

A.I Psychology Sociology

Linguistics

Art

Design

Engineering

ComputerScience

Philosophy

Physiology

Ergonomics Helpfacilities

Understandingthe user

Modellingthe user

Groupware

Aesthetic appeal

User interfacelayout

Faster

machinesFaster systemsMeans ofbuilding betterinterfaces

Language forcommands

Physical

capabilities

User body shape

Equipment design

Creatingconsistency


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5 measures :

Time to learn

Speed of performance Error rate

Retention over time

Subjective satisfaction

Goals of HCI


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Recognize patterns

Reason inductively

Communicate with multiple channels

Apply multiple strategies

Adapt to changes or unexpected events

What are thehuman good at?

From Ben Shneidermans designing user interfaces


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What are the Computergood at?

Sense stimuli outside humans range

Calculate fast and mechanical

Store large quantities and recall accurately

Response rapidly and consistently

Perform repetitive actions reliably

Maintain performance under heavy load

and extended time

From Ben Shneidermans designing user interfaces


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Synergic

Humans do things that human are good at

Computers do things that computers aregood at

The strength of one covers the weakness of

the other

The usertells the computerwhat they want

The computercommunicates results

What are the Interaction be?


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Physical

Anthropomorphic (height, left handed, etc.)

Age (mobility, dexterity, etc.) Cognitive

Perceptual

Sight, hearing, etc.

Personality

Including cultural factors

UserCharacteristic


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Life critical

Low error rate first and foremost

Justifies an enormous design and testing effort Custom Commercial

Speed and error rate

Office and Home

Easy learning, high user satisfaction, low cost

Creative

User needs assessment is very challenging

Human Factors in Systems


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Task System

Mental Models Sight

Sound

Hands

Voice

Task User

Software Models KeyboardMouse

Display

Speaker

Computer

Human

Userand System Models


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As a user, what do you want to know about a

machine for your interaction?

Disccussion : Mental Models


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Interactive Systems

Input Devices

Computer Output Devices

Interfaces


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Keyboard

Produces character codes

ASCII: American English

Latin-1: European languages

UNICODE: Any language

Pictographic languages need entry conventions

Keyboard shortcuts are important for data

entry VT-100 standard functions are common

But differing layouts can inhibit usability

And different conventions for standard tasks abound


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2-DDirect Manipulation

Match control actions with on-screen

behavior

Use a cursor for visual feedback if needed

Rotary devices

Mouse, trackball

Linear devices Touch pad, touch panel, touch screen, joystick

Rate devices

Laptop eraserhead


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Human Senses

Visual

Position/motion, color/contrast, symbols

Auditory

Position/motion, tones/colume, speech

Haptic

Mechanical, thermal, electrical, kinesthethic

Olfactory Smell, taste


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ComputerOutput

Image display

Fixed view, movable view, projection

Acoustic display

Headphones, speakers, within-ear monitors

Tactile display

vibrotactile, pneumatic, piezoelectric

Force feedback

dexterous handmaster, joystick, pen


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Inertial Display

Motion-based simulators

Olfactory Display Chemical (requires resupply)

Locomotive display

Stationary bicycle, treadmill, ...

Temperature Display

ComputerOutput


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Interaction Styles

Graphical User Interfaces (GUI)

Direct manipulation

Menus

Language-based interfaces

Command line interfaces

Interactive voice response systems

Virtual Reality (VR) Direct manipulation

Ubiquitous computing


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Windows

Spatial context

Icons Direct manipulation

Menus

Hierarchy

Pointing devices

Spatial interaction

WIMP Interface


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GUI Components

Windows (and panels)

Resize, drag, iconify, scroll, destroy

Selectors Menu bars, pulldown lists

Buttons

Labeled buttons, radio buttons, checkboxes

Icons (images)

Select, open, drag, group


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Direct Manipulation

Select a metaphor

Desktop, CD player, map,

Use icons to represent conceptual objects

Watch out for cultural differences

Manipulate those objects with feedback

Select (left/right/double click), move (drag/drop)


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Limitations of

Direct Manipulation

Understand the metaphor first

Not all tasks can be described as concreteobjects For example clipboard

Visual representation may be misleading Draw incorrect conclusions

Culture difference


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Menus

Conserve screen space by hiding functions

Menu bar, pop-up

Can hierarchically structured

By applications logic

By convention (e.g., where is the print function?)


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Limitations of Menus

Some functions are hidden

Need exploration

Need careful organization of menus Bad organization really increase time and errors

Tradeoff between breadth and depth

Too deep can become hard to find things

Too broad becomes direct manipulation


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Dynamic Queries

What to do when menus become too deep

Merges keyboard and direct manipulation

Select menu items by typing part of a word

After each letter, update the menu

Once the word is displayed, user can click on it

Example: Windows help index


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Language-Based Interfaces

Command Entry

Compact, flexible representation

Precise meanings Powerful in the hands of expert users

Natural Language

Intuitive to use

Powerful expressiveness


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Limitations to Language-Based

Interfaces What can be done may not be apparent

Easy to over or underestimate, thus cause

frustration

NL could be vague, ambiguous, and

ungrammatical, context dependent

High demand on systems ability

Commands are difficult for nave users

Push away new users


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Text Retrieval Interfaces

A practical, compromised NL interface

NL input, but only keywords

Not try to understand, just shallow processing

Example: MIRACLE system at

http://tides.umiacs.umd.edu/CLIR_interface


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Aural Perception

We respond to sounds without prior focus

Lack of focus limits simultaneous stimuli

Absolute amplitude & pitch hard to interpret

But changes stand out clearly

Stereo effect provides a sense of direction

Relative amplitude, phase difference


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Speech Output

Replay of digitized speech clips

High fidelity, but limited vocabulary

Speech Synthesis Generate spoken output from unrestricted input

Based on pronunciation rules and lists of exceptions

Sounds unnatural due to misplaced emphasis

Prosody-guided speech synthesis

Use pronunciation of similar words as a guide


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AuditoryDisplay

Nonspeech audio output for user interfaces

Same objectives as graphical output:

Alert the user to exceptional conditions Provide ubiquitous feedback

Present information

But different characteristics

Effective even without focus

Fairly low resolution


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AuditoryDisplayDesign

Need a metaphor

Clock ticking, alarm bells, keyboard clicks, etc.

Channel is easily overloaded Focus helps manage cognative load

Changes are more useful than values

Pitch, amplitude, position, harmonics, etc.


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An Auditory ImageDisplay

Display 2-D images using only sound

Sweep from left to right every second

Audible pause and click between sweeps

Top pixels are high frequency, bottom are low

Blind users can detect objects and motion

Time indicates horizontal position

Pitch indicates vertical position

Sweep-to-sweep differences indicate motion

http://www.visualprosthesis.com/voice.htm


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Interactive Voice Response

Systems Operate without graphical interfaces

Hands-free operation (e.g., driving)

Telephone access

Built on three technologies

Speech recognition (input)

Text-to-speech (output) Dialog management (control)

Example: TellMe (1-800-555-TELL)


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Dialogue Management

Turn-taking

User initiative

System initiative (allows smaller vocabulary) Mixed initiative (e.g., barge in)

Interaction style

Direct answers

Achieving conversational goals


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Summary

HCI design starts with user needs + abilities

Users have a wide range of both

Users must understand their tools And these tools can learn about their user!

Many techniques are available

Direct manipulation, languages, menus, etc.

Choosing the right technique is important


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By : Pn Nur Saadah Binti Fathil

Mental Models

How the user thinks the machine works

What actions can be taken?

What results are expected from an action?

How should system output be interpreted?

Mental models exist at many levels

Hardware, operating system, and network

Application programs

Information resources

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