• 17:15 Universal accessibility

General Principles
Vanderheiden (1997)

• Use: equitable, flexible, simple and intuitive.
• Perceptible information and error tolerance.
• Low physical effort and appropriate size and space for approach.

Guidelines for Elderly
Czaja (1997)

• Contrast, screen glare, object size
• Minimal info, consistent location, group
• Highlight, color discrimination, key label
• Clear icons, practice
• Minimal demands on memory
• Consistency, simplicity (e.g. online help)

Web Content Guidelines (W3C) http://www.w3.org/TR/WAI-WEBCONTENT

• Auditory/visual alternatives/not color alone
• Markup and style sheets
• Natural language, tables, pages
• User control, access of embedded UIs
• Device independence, interim solutions
• W3C technologies, context information
• Clear navigation and simple documents

• Guidelines are available
• A coherent, complete, well-founded and practical set is lacking
• Techniques for application of the guidelines are scarce

• Map user requirements on current support functions
• Prioritize according to "Web-service objectives"
• Estimate implementation costs

• Individualization of Web-interfaces is needed to realize "Universal Accessibility"
• Design for all results in adaptive interfaces (no "boring uniformity")
• Elderly users need more navigation support

• Often referred to as I18N
• Could just as well be D16N: Deparochialisation

• We all walk, eat, sleep, talk
• Culture is the difference
• Cultures are everywhere: national, gender, regional, technical...

• The Web: a European invention
  (An Englishman and a Dutch-speaking Belgian working on the border between Switzerland and France)
• For the first time Europeans can write their names in a platform-independent way

• Email and news on the other hand were American inventions
• Greeks (and many others) have to use an agreed mapping to communicate:
• E auto den to perimena. Na afhsei pisw tou ton Darren Campbell kai ton Ato Boldon??? Kai me 20:09??? Pou sta hmitelika ekane 20:20 kai
  panellhnio rekor? Auta ta pragmata ginontai mono stous Olympiakous. Mpravo !

• Make people feel at home
• Build trust (important for e-commerce)
• Even spelling in your own language area
• Why did Toys R Us fail in the Netherlands?
• Packing books

• Aaron Marcus 1993
  (This is for a
  European Male)

• Maybe worth a design competition…

• Don’t require fields that not everyone has
• Don’t impose an order on the fields

• Don’t use all number formats

• Beware of generating beeps from an application

• Don’t use a French flag to represent the French language: there are many languages in France, and there are many other countries that speak French. (And the same for all other flags)

• Makes the user feel at home.

• Can be insulting
• Most combination of hand/finger positions is an insult somewhere in the world, even ‘Thumbs up’!
• Avoid visual puns, ‘run’, ‘step’, ‘save’, ‘change’, even ‘server’

• Don’t assume standard meanings to characters
• "?" vs ";" vs "i"
• #

• Checkbox: "x" can mean "no", tick doesn’t necessarily mean yes
• This is a tick on homework in the Netherlands:

• Culture is in the details
• Being aware of the issues is an important first step
• Making the user feel at home builds trust

• Bear in mind that there are many different sorts of platforms
• The types are expanding
• Phones, handheld, Web TV, computers, aural browsers, ...

• Provide equivalents for sound and visuals
• Don’t rely on colour alone
• Use markup and style sheets, properly
• Clarify natural language use
• Tables should transform gracefully
• Use of new technologies should transform
• Allow control of time-based changes

• Ensure embedded interfaces are accessible
• Be device-independent
• Use interim solutions
• Use W3C technologies and guidelines
• Provide context and orientation
• Provide clear navigation
• Documents should be clear and simple

• ‘Bobby’: www.cast.org/bobby

• HTML is really a structure language
• Avoid display-oriented tags (font, blink, …)
• Avoid the use of images for text
• Avoid using tables for layout
• Always use the ALT attribute on images
• Even better: use <object>
• Don’t assume anything about pixels!

• Instead of using HTML as presentation language, use a stylesheet language, such as CSS

• HTML (up to now) has been an SGML application.
• SGML is intended to define the structure of documents

• These classifications often have semantic significance (e.g. <H1>)
• <I> and <B> were mistakes, use <EM> and <STRONG> instead

• Netscape started to add their own tags, based on the idea that with their market penetration they could get a head start.
• Unfortunately most tags added are presentation-oriented tags such as <BLINK> and <FONT>

• Presentation tags do specify how the item should look, and have no inherent semantics – they do not fit in the structure orientation of standard HTML; Microsoft also followed suit with their tags

• In order to get HTML back to being a structure language, W3C hosts work on Style Sheets, and producing a Style Sheet Language CSS – Cascading Style Sheets.

• easy to write
• easy to implement
• has a development path.
• CSS is a 90% solution
• For all typesetting possibilities XSL is being developed

• CSS is a language that allows you to specify how a document, or set of documents, should look.

• Separates content from presentation
• Makes HTML a structure language again
• Makes HTML easier to write (and read)
• All HTML styles (and more) are possible
• You can define a house style in one file
• Accessible for the sight-impaired
• Still visible on non-CSS browsers

• CSS is also an enabling technology for XML (more later)

• In general a valid CSS1 style sheet is also a valid CSS2 style sheet.
• In general a CSS2 style sheet can be read and used by a CSS1-supporting browser.

• Presentation is not hard-wired in the HTML
• Users can make their own choices (font size, colours, etc), and override the documents
• Pages load faster

• Pages become more accessible for the sight-impaired (who can use speech browsers)
• Pages are viewable on a wider range of platform types

• Documents become easier to write (and read)
• Presentation is centralised
• Easier to provide a house style
• Wider range of presentation possibilities
• Separation of concerns

• Apart from standard HTML effects, CSS can generate a wide range of presentational effects

• Users can specify a language preference; the server can identify this and serve pages in that language
• Accept-Language:

• <head>

• Use HTML to structure your documents
• Consider switching to XML

• XML is going to replace HTML as delivery language.
• XHTML is an XML-ised version of HTML

• Introduction
• What specifications can and can’t do
• How and when to use specifications
• Specifications in the design process
• Different techniques, example
• Conclusions

• specification means abstraction
• different specification techniques stress different features
• specifications can range from mock-up and natural language to formal methods

• identification of system properties
• error and inconsistency detection
• specifications can establish communication between designers and programmers
• (formal) specifications can be used to create (interactive) prototypes

• guarantee a system is perfect
• avoid miscommunication
• 7 myths and more

• complex systems (e.g. multi-agent systems, multimodal systems)
• trustworthy systems (e.g. e-commerce)
• not for complete systems

• use formal specification linked to empirical methods for design and evaluation
• specification techniques can be used throughout the entire design process
• the design process used does not matter

• Empirical methods (like usability engineering or the prototyping approach) have much attention for the user’s needs.
• Specification techniques add attention for the system’s behaviour in critical situations (see benefits)

• GOMS
• GTA
• Z
• CSP
• ...

• Goals, Operators, Methods and Selection (GOMS).
  Hierarchical description of the user’s goals and tasks
• Groupware Task Analysis (GTA). Task modeling in environments where many people interact with a system

• Z. Mathematical description of entities and their relations. Best fitted for the description of static properties of systems
• CSP. Algebraic description of interacting, dynamic processes.

• game to play slide puzzles
• specified by using natural language and CSP-alike

• the use of the specification in the design process determines the choice of technique
• use combinations (e.g. Z or CSP combined with natural language)

• Situation Awareness

• General Structure

• Split into groups