disabilities & older people

students in biology

concepts of accessibility, usability and user experience

the iterative user-centred design lifecycle

strengths & weaknesses & appropriate use

user friendly

easy to use

✅ Effectiveness

✅ efficiency

✅ satisfaction

✅ flexibility

✅ learnability

✅ memorability

✅ safety

✅ users

✅ goals

✅ contexts

✅ usability is a sub-set of accessibility

✅ accessibility as a sub-set of usability

usability -> mainstream (i.e. non-disabled, younger) users

accessibility -> disabled and older users

universal design

design for all

user experience, initially popularized by him in 1998

✅ Likability

✅ Pleasure

✅ Comfort

✅ Trust

task-oriented aspects

beauty

challenge

stimulation

self-expression

task completion times and error rates for efficiency

their interaction with them

removal of barriers or problems

maximize positive aspects of eSystem

✅ study existing guidelines

✅ interview current & potential users

✅ conduct an ethnographic & context of use

track subsequent design & development

update to reflect changes in understanding user requirements

Common Industry Specification for Usability Requirements

✅ explore the design space

❌ immediately settling on one design

simple & complex

sketches on paper & animations with interactivity

people involve in evaluation

address functionality of eSystem

explore particular design problems

whether feasible or not

feed back into design process

⭐ heart of the process

experts

users

track

feed back

people are such complex entities

20+ iterations

main design & development -> a month -> 3~4 iteration

preparation -> long time -> 15+ iterations

go on in parallel with back-end development

usability, accessibility and user experience

✅ evaluation in real context

understanding users

design process

this version & subsequent versions

✅ consider accessibility from beginning -> cost min

✅ design for all

✅ barrier free design

✅ inclusive design

❌ can't be met in practice

❌ frighten designers and developers

✅ not need to solve all the accessibility problems

✅ screen readers

✅ screen magnification programs

✅ a variety of alternative input devices

✅ ...

✅ don't use an assistive technology

✅ do use an assistive technology

integrated into the iterative user-centred design process

✅ Evaluations conducted by experts

✅ Evaluations using models and simulations

✅ Evaluation with users or potential users

✅ Evaluation of data collected during eSystem usage

P1 & P2 & P3

14 high level accessibility guidelines

65 specific checkpoints

A & AA & AAA

✅ perceivable

✅ operable

✅ understandable

✅ robust

Human Ability and Accessibility Centre

O’Connor (2007)

resources at Sun Accessibility 11

resources at the Microsoft Accessibility Developer Center

✅ Visibility of system status

✅ Match between system and the real world

✅ User control and freedom

✅ Consistency and standards

✅ Error prevention

✅ Recognition rather than recall

✅ Flexibility and efficiency of use

✅ Aesthetic and minimalist design

✅ Help and documentation

✅ Strive for consistency

✅ Enable frequent users to use shortcuts

✅ Offer informative feedback

✅ Design dialogue to yield closure

✅ Offer simple error handling

✅ Permit easy reversal of actions

✅ Support internal locus of control

✅ Reduce short-term memory load

207 guidelines

very time consuming to employ in evaluation

more complete and easier to use than the equivalent ISO

✅ learn -> large number of guidelines & efforts

✅ evaluation -> time consuming

✅ user type

✅ task

❎ environmental conditions

prototypes & full implementations

not contain basic accessibility and usability problems

❌ Bobby Tool -> no longer available

✅ LIFT

✅ Web Static Analyzer Tool

❌ basic problems & limited scope of usability issues

prototypes

too many pages / screens to user-based evaluation

not possible to obtain actual users

insufficient time for user testing

train developers

review

inspection

walkthrough

✅ evaluators
✅ a set of heuristics
✅ rate the potential problems individually -> how severe
✅ a four level rating scheme is used (1,2,3,4)
✅ better results are obtained by trained experts

✅ asking the evaluator to step through typical user tasks
heuristic evaluation + cognitive walkthrough

✅ heuristics are a useful training aid & value is not clear

each user action -> evaluator analyses
interface
feedback

user & developer & human factor people

a scenario & discuss & dialogue

Heuristic evaluation

Expert Walkthrough Evaluations

on an ad hoc basis by an expert

employ user evaluation instead

✅ a representative set of pages

✅ a range of graphical browsers

1. turn off images
2. turn off the sound
3. use browser controls to vary font-size
4. test with different screen resolution
5. change the display colour to greyscale
6. without using the mouse

AIS Toolbar

Accessibar add-on

WAVE Toolbar

JAWS

WindowEyes

a full accessibility audit

✅ UWEM and WAI websites

✅ simpler and quicker

✅ a wider range of users and tasks

❌ emphasize more superficial problems

❌ not scale well for complex interfaces

models can be constructed economically

user testing is not practical

time to complete tasks is critical

✅ Keystroke Level Model

✅ ACT-R model

other methods are impracticable

✅ max -> all stages of development,

✅ min -> the final stage of development

users

developers & managers

✅ no way to find all usability issues in one evaluation

✅ previous similar usability evaluation

✅ initial results of an ongoing study

✅ 0.08~0.42

✅ 3~19 -> 80% problems

✅ 4~28 -> 90% problems

✅ complex website -> lower probabilities

✅ test with at least 8 users

✅remote evaluation

✅ assistive technology

✅ the needs of participants in the evaluation

✅ how will they come

✅ the location accessible

✅ pace of evaluation suitable

✅ Kansei techniques

✅ rating scales and questionnaires -> simplest

✅ AttrakDiff -> user experience

improve an existing eSystem

Provides non-intrusive data

entrance and exit pages

economical & feedback

frequency of particular paths through the site

the extent to which search it successful

difficult to track individual behaviour

particular user groups and tasks

data point

anonymously to developer

guide future design decision