Wikipedia:Accessibility

From Wikipedia, the free encyclopedia

This guideline is a part of the English Wikipedia's Manual of Style. Use common sense in applying it; it will have occasional exceptions. Please ensure that any edits to this page reflect consensus.

Shortcuts: WP:ACCESS WP:ACCESSIBILITY

Accessibility is the goal of making web pages easier to navigate and read. While this is primarily intended to assist those with disabilities, it can be helpful to all readers. Articles adhering to the following guidelines are easier to read and edit by those Wikipedians with and without disabilities.

Contents 1 Article structure 1.1 Lead section 1.2 Headings 1.3 Section structure 1.4 Resolution 2 Text 3 Links 4 Color 5 Block elements 5.1 Lists 5.1.1 Horizontal lists 5.2 Tables 5.2.1 Data tables 5.2.2 Layout tables 5.3 Infoboxes 6 Other languages 7 Images 8 Styles and markup options 8.1 Users with limited CSS/JavaScript support 9 Keyboard shortcuts 10 See also 11 References 12 External links

[edit] Article structure

[edit] Lead section

As explained in detail at Wikipedia:Lead section#Elements of the lead, the lead section may contain optional elements presented in the following order: disambiguation links (dablinks), maintenance tags, infoboxes, images, navigational boxes (navigational templates), introductory text, and table of contents, moving to the heading of the first section.

[edit] Headings

Headings should be descriptive and in a consistent order (See also—References—Further reading—External links).

Headings should be nested sequentially, starting with level 2 (==), then level 3 (===) and so on (level 1 is not used, as this is the auto-generated page title), neither using random heading levels (e.g. selected for emphasis, which is not the purpose of headings), nor skipping parts of the sequence.

Heading use (and misuse) examples

Correct	Random/chaotic	Skipping levels
[Article lead here] ==Section== [level 2] ===Sub-section=== [3] ==Section== [2] ===Sub-section=== [3] ====Sub-sub-section==== [4] ==Section== [2]	[Article lead here] ====Section?==== [4] ===Section?=== [3] ==Section?== [2] ==Section?== [2] ====Section?==== [4] ===Section?=== [2]	[Article lead here] [Level-2 section missing here] ===Section?=== [3] ==Section== [2] [Level-3 sub-section missing here] ====Sub-section?==== [4] ==Section== [2]

[edit] Section structure

As explained above for the lead section, each section should have a specific structure:

<!-- CORRECT CODE -->
== Foo bars ==
{{main|Foo bar}}
{{cleanup-section}}

[[Image:...|Typical Foo bar]]

A foo bar ...

Note also that the image should be inside the section it belongs to (after the header and after any links to other articles), and not just before the header for similar reasons.

[edit] Resolution

Wikipedia articles should be accessible to readers using devices with small screens, or to readers using monitors with a low resolution. The lowest resolution that it is considered possible to support without adversely affecting other users is 800x600; all articles should look acceptable at this resolution without excessive horizontal scrolling. This is sometimes an issue in articles with multiple images on both sides of the screen; although lower resolutions will tend to stretch paragraphs vertically, moving images apart in that direction, be careful not to add images or other floating content on both sides of the screen simultaneously. Large tables and images can also create problems; sometimes horizontal scrolling is unavoidable, but consider restructuring wide tables to extend vertically rather than horizontally.

[edit] Text

1. Spelling and grammar errors can dramatically affect the sound of the text ("initative" instead of "initiative"), which can make the text more difficult to read.
2. Don't use strikethrough to remove objectionable text in articles. Either comment it out with "<!--" and "-->" or remove it entirely. By default, most screen readers do not indicate text attributes (bold, italic, underline), so struck-out text is read normally along with any other text. (Editors who participate in Wikipedia policy and XfD debates are advised to turn on the sounding of text attributes when doing so, as struck text is very common in Wikipedia-internal discussions.)
3. Provide a transliteration for all text in a non Latin writing system. Screen readers without Unicode support will read a character outside Latin-1 as a question mark, and even in the latest version of JAWS, the most popular screen reader, Unicode characters are very difficult to read.
4. Don't use techniques that require physical action to provide information, such as tooltips or any other "hover" text.
5. When editing, never break up a line unless absolutely necessary, as the easiest way to edit with a screen reader is to navigate line by line.
6. You can change your individual display to show footnotes in full sized text by adding
   .references-small { font-size: 100%; }
   to your Special:Mypage/monobook.css

[edit] Links

1. Do not overlink. Screen readers put each link on its own line.
2. Create good link descriptions, especially for external links (avoid "click here!", "this" or (more...) as in "today's featured article" section of the home page).^[1][2]
3. Avoid putting links in section headings. Some screen readers, such as versions of JAWS prior to 7.1, have significant difficulty correctly rendering such headers. Additionally, special characters such as brackets ("[") and curley brackets ("{") are invalid characters in HTML, which causes section headers to be invalid as HTML anchors. Using wikitext in section headers makes it more difficult to link to them internally as well.
4. Use as little code as possible, so the text in the edit window is easier to read (for example: don't use [[clock|clocks]] when [[clock]]s will work).
5. Do not use Unicode characters as icons, use an icon with alt text instead. For example, a character like "→" can not be reproduced into useful text by a screen reader, and will usually be read as a question mark.

[edit] Color

Shortcuts: WP:COLOR WP:COLOUR WP:COLORS

Colors are most commonly found in Wikipedia articles within templates and tables. To view the colors available, see List of colors. For technical assistance on how colors are used, see Wikipedia:Using colors.

Articles that use color should keep accessibility in mind, as follows:

• Ensure that color is not the only way used to convey important information. Especially, do not use colored text unless its status is also indicated using another method such as italic emphasis or footnote labels. Otherwise, blind users or readers accessing Wikipedia through a printout or device without a color screen will not receive that information.
• Many readers of Wikipedia may be partially or fully color blind. Ensure that the color combinations used in Wikipedia (infoboxes, navigational boxes, graphs, etc.) have an adequate contrast. Use a color scheme generator to select the colors, and tools for simulating color blind vision (colorfilter.wickline.org or vischeck.com) to check the result.
• Overriding a link color, especially to red, is confusing and should be avoided.
• Be aware of the contrast of both plain text and the blue link text with the background color and avoid clashes where possible (such as blue writing on a red background).
• If an article overuses colors, add the {{Overcolored}} tag to the top of the article, producing:

This article may overuse color, making it hard to understand for color blind users. See the category page and WP:Colors for guidelines.

You can add {{Overcoloured}} instead, if the article uses British spelling.

• Web pages can be checked on-line with AccessColor, which analyzes the HTML source for a web page and the associated Cascading Style Sheets, and then calculates the color contrast and color brightness between the text and background colors to check that they conform with version 1.0 of the Web Content Accessibility Guidelines.
• Suitable color contrast for people with vision impairments, including color blindness, can be tested with the Colour Contrast Analyser or a specific Firefox extension that use the draft algorithms from the World Wide Web Consortium.

[edit] Block elements

[edit] Lists

Do not separate list items by more than one line-break. If list items are separated by more than one line break, the HTML list tags will be ended. For example:

#One is a good number.
#Two is a better number.

#Three is the best number in the world.

#But the number four should not be mentioned at all costs.

appears as:

1. One is a good number.
2. Two is a better number.

1. Three is the best number in the world.

1. But the number four should not be mentioned at all costs.

The same applies to unordered lists (using * instead of #).

[edit] Horizontal lists

For lists running across the page, the template {{flatlist}} and its partner {{endflatlist}} are available, to improve accessibility and semantic meaningfulness by marking up what is clearly a list, as such, rather than characters which are read out (e.g. "one dot two dot three dot...") by the kind of assistive software used by, for example, people who are blind. Alternatively, in templates and the like, such lists may be styled with the class "horizontal".

[edit] Tables

Screen readers and other web browsing tools make use of specific table tags to help users navigate the data contained within them.

Use the correct wikitable pipe syntax to take advantage of all the features available. See meta:Help:Tables for more information on the special syntax used for tables. Do not solely use formatting, either from CSS or hardcoded styles, to create semantic meaning (eg, changing background colour).

The technique of creating a multi-line infobox using matching embedded HTML <br/> tags in adjacent cells creates a visual row not reflected in the HTML table structure. This is a problem for users of screen readers which read tables cell by cell, html row by html row, not visual row by visual row. WikiProject Usability/Infobox accessibility is addressing this problem.

[edit] Data tables

{| 
|+ [caption text]
|-
! [column header 1] !! [column header 2] !! [column header 3]
|-
! [row header 1]
| [normal cell 1,2] || [normal cell 1,3]
|-
! [row header 2]
| [normal cell 2,2] || [normal cell 2,3]
…
|}

Caption ( |+ )

A caption is a table's title, describing its nature.^[3]

Row & column headers ( ! )

Like the caption, these help present the information in a logical structure to visitors. They can have the headers read first, and then navigate the related data.^[4]

Voice browsers might read aloud this data table in the following order:^[5]

Caption: [caption text]
[column header 1]: [row header 1], [column header 2]: [cell 1,2], [column header 3]: [cell 1,3]
[column header 1]: [row header 2], [column header 2]: [cell 2,2], [column header 3]: [cell 2,3]
…

Note that each column header is repeated when reading every row, so an abbreviation could be added to long headers using the abbr="…" attribute, for example:

{|
|+ [caption text]
|-
! abbr="Wikipedian" | Wikipedia editor
! abbr="Edits"      | Number of edits
! Last edit
! abbr="Donations"  | Donations (US$)
|-
…

In this example all column headers have an abbreviation except the column with the date of the last edit, which is short enough.

It can cause problems if a column or row header contains a colspan/rowspan. If there is a colspan in the first table row, both columns will be described the same by the voice browser; a similar thing happens if the first table column has rows joined by a rowspan. This may be mitigated by other aspects of the table; for instance the table may be chronologically organized, or the two columns may contain, respectively, a hard number and a percentage with a percent sign.

It can cause problems if cells that are not in the first row or column contain a colspan/rowspan. If the content of the joined cells does not actually apply to all of the corresponding cells in the first row or column, then the voice browser may incorrectly report the header that applies to those cells.

It can cause problems if the first column in a row has non-text comment such as a photograph (unless the photograph contains an alt attribute) or a color without explanatory text.

[edit] Layout tables

Some navboxes, series templates, and infoboxes are made using tables.

Avoid using tables for layout purposes only. The best option is to use HTML's <div> blocks and style attributes because they provide flexibility. For example, see {{Dynamic navigation box}}.

For simple layouts tables can be an option. Especially if the only point of the table is to get a floating effect, then align="right" etc. will work with some browsers not supporting CSS at all. This is in fact a verbose approximation of <div> plus CSS, and not the design sin known as (nested) "table layout".

However, to avoid accessibility barriers, when using tables for layout purposes don't use any caption, row, or column headers, and also no summary attribute. These structural table elements should be used only for data tables. Don't use structural elements for presentation purposes, use style sheets. For Wiki table markup this means to avoid "!" (= <th> in XHTML) in such cases:

{| class="toccolours" width="94%"
| align="center" bgcolor="#ccccff" | '''Title'''
|-
| [normal cell] || [normal cell]
|-
| [normal cell] || [normal cell]
|}

For example, see {{NavigationBox}}

[edit] Infoboxes

See the HTML breaks problem.

[edit] Other languages

Non-English words or phrases should be encased in {{lang}}, which uses ISO639 language codes, thus:

{{lang|fr|Assemblée nationale}}

which renders as

Assemblée nationale.

[edit] Images

1. Images should include alt text that acts as a substitute for the image for blind readers, search-spiders and other non-visual users. This guideline includes alt text for LaTeX-formatted equations in <math> mode.
2. Images should contain a caption, either using the built in image syntax or a secondary line of text. The caption should concisely describe the meaning of the image, the essential information it is trying to convey.
3. Where possible, any charts or diagrams should have a text equivalent, or should be well-described so that users who can't see the image can gain some understanding of the concept.
4. Detailed image descriptions, where not appropriate for an article, should be placed on the image description page, with a note saying that activating the image link will lead to a more detailed description.
5. Images should be inside the section they belong to (after the heading and after any links to other articles), and not in the heading.
6. When possible, do not force oversizing of images that override the default user preferences. Some users need to configure their systems to display large text; forced large thumbnails can leave little width for text, making reading difficult.

[edit] Styles and markup options

In general, articles should use wikimarkup in preference to the limited set of allowed HTML elements. In particular, do not use the HTML style tags <i> and <b> to format text; it is preferable to use Wiki markup '' or ''', or logical style tags. Of course there are natural exceptions: it may be beneficial to use <u></u> tags to indicate something like an example of an unclickable link. The <font> tag should also be avoided in article text; use logical style tags like <em>, <code>, or <strong> to emphasise semantic differences. Use <small> and <big> semantic tags to change font size, rather than setting it explicitly with the font-size= style attribute.

In general, styles for tables and other block-level elements should be set using CSS classes, not with inline style attributes. This is because the site-wide CSS is more carefully tested to ensure compatibility with a wide range of browsers; it also creates a greater degree of professionalism by ensuring a consistent appearance between articles. Deviations from standard conventions are acceptable where they create a semantic distinction (for instance, the infoboxes and navigational templates relating to The Simpsons use a yellow colour-scheme instead of the customary mauve, to tie in with the dominant colour in the series) but should not be used gratuitously.

[edit] Users with limited CSS/JavaScript support

Wikipedia articles should be accessible to readers using browsers and devices which have limited or no support for JavaScript or Cascading Style Sheets. At the same time, it is recognised that it is impossible to provide the same quality of appearance to such users without unnecessarily avoiding features that would benefit users with more capable browsers. As such, features which would cause content to be hidden or corrupted when CSS and/or JavaScript is unavailable must not be used. This includes techniques such as the hiddenStructure method for hiding table content – which produces incomprehensible output without CSS – and some implementations of the NavFrame collapsing code – which can make content inaccessible without JavaScript support. However, consideration for users without CSS or JavaScript should extend mainly to making sure that their reading experience is possible; it is recognised that it will inevitably be inferior.

To accommodate these considerations, test any potentially disruptive changes with JavaScript and/or CSS disabled. In Firefox, this can be done easily with the WebDeveloper extension; JavaScript can be disabled in IE in the 'Options' screen. Be particularly careful with inline CSS effects, which are not supported by several browsers, media, and XHTML versions.

[edit] Keyboard shortcuts

Numerous keyboard shortcuts for common Wikipedia tasks exist by default. They can be disabled.

[edit] See also

• Web Accessibility Initiative (WAI)
• Wikipedia:Accessibility advocates
• Wikipedia:Using JAWS
• Wikipedia:WikiProject Accessibility
• Wikipedia:WikiProject Usability

[edit] References

1. ^ G91: Providing link text that describes the purpose of a link, techniques for WCAG 2.0
2. ^ F84: Failure of Success Criterion 2.4.9 due to using a non-specific link such as "click here" or "more" without a mechanism to change the link text to specific text., Techniques for WCAG 2.0
3. ^ http://www.w3.org/TR/REC-html40/struct/tables.html#h-11.2.2
4. ^ http://www.w3.org/TR/REC-html40/struct/tables.html#edef-TH
5. ^ http://www.w3.org/TR/WCAG10-HTML-TECHS/#identifying-table-rows-columns

• Clark, Joe (2003). Building Accessible Websites. New Riders Press. ISBN 0-7357-1150-X. http://www.joeclark.org/book/. 
• Pilgrim, Mark (2002). "Dive Into Accessibility: 30 days to a more accessible web site". http://diveintoaccessibility.org/. Retrieved 2006-05-07. 

[edit] External links

• 10 Quick Tips to Make Accessible Web Sites, from WAI
• Colorblind web page filter
• Creating Accessible Tables, from WebAIM
• Essential Components of Web Accessibility, from WAI
• Introduction to Web Accessibility, from WAI
• MediaWiki bug 367: Markup accessibility issues (tracking)