1 Population Diversity and Universal Accessibility Jinjuan Feng

Overview Universal accessibility Definition Dimensions Three categories of human capabilities Physical capabilities Perceptual capabilities Cognitive capabilities Human capabilities according to age General design guidelines for universal accessibility

Universal accessibility (UA) How can information and communications services be made accessible for every citizen? Seniors and children People with disabilities Experienced users versus novice users Time wasted on computer: 5.1 hour/week Access to computer and internet Accessibility does not equal to usability

Dimensions of UA Human capabilities Physical Perceptual Cognitive Age Context of use

Physical abilities Physical abilities refers to functions achieved by human motor system, mainly affects the ability of inputting data to the computer Physical abilities that affect computer users mainly relate with finger, hand and arm There is no average user, either Compromises or multiple versions of a system Physical measurement of human dimensions not enough, must also consider dynamic measures: reach, strength speed

Cognitive abilities The human ability to interpret sensory input rapidly and to initiate complex actions Classification of human cognitive processes: Long-term and semantic memory Short-term and working memory Problem solving and reasoning Decision making and risk assessment Language communication and comprehension Search, imagery, and sensory memory Learning, skill development, knowledge acquisition and concept attainment

Perceptual abilities Functions achieved by human perceptual systems, mainly affects the ability of receiving the data output by the the computer Variances of the user population's sense perception Vision: Touch: keyboard and touchscreen sensitivity Hearing: audio clues must be distinct

Cognitive and perceptual abilities Factors affecting perceptual and motor performance: Arousal and vigilance Fatigue and sleep deprivation Perceptual (mental) load Knowledge of results and feedback Monotony and boredom Sensory deprivation Nutrition and diet Fear, anxiety, mood, and emotion Drugs, smoking, and alcohol Physiological rhythms But note, in any application, background experience and knowledge in the task domain and the interface domain play key roles in learning and performance

Group Exercise: Personal Differences Work individually, write down as many as perspectives that humans are different from each other E.g. gender, race, hair color… Among them, mark those that affect the use of computers

Personality differences There is no set taxonomy for identifying user personality types Designers must be aware that populations are subdivided and that these subdivisions have various responses to different stimuli Myers-Briggs Type Indicator (MBTI) extroversion versus introversion sensing versus intuition perceptive versus judging feeling versus thinking

Designing for users with disabilities

Users with cognitive disabilities Cognitive impairments (CI) IQ: 100 is average. 70 to 130 is considered normal. People with IQ of below 70 may have mild to severe mental retardation Relationship to security CI may hinder the users’ ability to understand and learn security and privacy mechanisms and procedures CI would affect the use of S&P mechanisms that require memory and recognition(e.g., password, CAPTCHA).

Users with cognitive disabilities Interface design considerations Attention Memory loss and dementia Visuospatial, Iconic, and verbal abilities Technologies to improve interaction Software to prompt communication for non speaking people Software supporting dementia

Users with physical disabilities Physical disabilities Health-condition induced PIs: Mainly injuries or diseases affecting hands or arms SCI, RSI, ALS, etc. Dimensions of PI Permanent or temporary Continuous or intermittent Progressive, regressive, or static Severity of PI

Users with physical disabilities Physical disabilities affect the ability to interact with S&P applications, such as entering passwords. Existing S&P applications are not adapted to the possible alternative input techniques. Technologies to improve interaction Keyboard and mouse modification Multi-Modal Speech recognition Head mounted devices Eye tracking Electrophysiological technology

Users with perceptual disabilities Perceptual disabilities Visual function impairments affect computer usage profoundly Visual acuity Contrast sensitivity Visual field Color vision Auditory impairments Conductive or sensorineural Congenital, prelingual or postlingual Can affect learning and speech Speech impairments Can affect interaction ability, especially in ubiquitous computing environment

Demo: Effect of Red-Green Color Blindness

Users with perceptual disabilities Technologies to improve interaction Perceptual interfaces Multimedia interfaces Multimodal interfaces Adaptive interfaces Synthetic and digitized speech Nonspeech sounds Auditory icons

Group exercise If you are designing a website for the national federation of the blind, what special concerns should you take care of? What is the challenge of designing a online tutoring database course for blind users?

Comments to exercise National Federation of the Blind Limit the use of images, graphics, and animations Make sure all image and links are accompanied with text Online database tutor course How to deliver diagrams to the blind users Audio interpretation Tactile interaction

Elderly Users Higher percentage and wider needs 65 years or older: 13% in 2000, 20% by 2030 Wider needs: work, home, health care As people age, all three types of human capabilities gradually decrease, affecting their ability to use S&P applications. Sensory processes Motor skills Cognitive abilities

Elderly Users Designing for elderly users Hardware considerations Display screen Keyboard Instructions and manuals Input devices Keyboard and mouse Pen and touch screen, etc. Software considerations Easy to learn Cognitive demand

Group exercise Suppose you are asked to design a website for a senior living community, what will you do to fit the need of the elder users? Perceptually Cognitively Physically

Comments to exercise Perceptual Maximize the contrast between characters and screen background Avoid small targets and characters Highlight important screen information Avoid color discriminations among colors of the same hue Cognitive Minimize irrelevant screen information Present screen information in consistent locations Clearly label keys and icons Use icons that are easily discriminated and meaningful Avoid complex command languages Physically Limit the number of icons on screen Maximize the size of the icons Increase the distance between those icons

Design for children How are children different? Dexterity Motor control Physical size Speech Prefer speech recognition than typing

Design for children Reading Reading level Font size Background knowledge Interaction style Easily distractible Use computer as a group

Security & Privacy for Children Due to the cognitive and mental capabilities, children are particularly vulnerable to security and privacy violations. Children may not be able to understand the need for S&P mechanisms and procedures Children have problem learning and using many S&P applications due to limited reading and typing skills, as well as memory capabilities 30

Situationally induced impairments Situationally-induced impairments refers to loss of functionality due to specific situations Situationally-induced impairments are becoming more important with the popularity of mobile computing

Group exercise Think of three examples of situationally-induced impairments that affect people’s Physically capabilities Perceptual capabilities Cognitive capabilities For each example, discuss the specific body functions affected the type of tasks affected

Comments to exercise Physical capabilities Walking, in a car driving on a pumpy road, cold weather, noise Key in data using a PDA, entering data using speech recognition Perceptual capabilities Noise Listening to the phone Cognitive capabilities Using mobile phone driving

General design guidelines Designers must plan early to accommodate users with disabilities Early planning is more cost efficient than adding on later Businesses must comply with the "Americans With Disabilities" Act for some applications