Accessibility Statement
This accessibility statement, dated January 2007, applies to the web pages created during vPlants' redesign in late 2006 early 2007. The static and live pages created before this are in the process of being replaced.
Access keys
Most browsers support jumping to specific links by typing keys defined on the web site. On Windows, you can press ALT + an access key; on Macintosh, you can press Control + an access key.
Most pages on this site define the following access keys:
- Access key 1
- - Home page
- Access key 2
- - Skip to main content
- Access key 3
- - Top of page
- Access key 4
- - Search form (if present on page)
- Access key 5
- - Advanced Search
- Access key 6
- - Help Guide
- Access key 7
- - Site Map
- Access key 8
- - Contact Us
- Access key 9
- - Feedback
- Access key 0
- - Accessibility statement
Standards compliance
- The home page and static pages validate as HTML 4.01 Strict. For example, check the home page for HTML validity.
- The home page, static pages, and live pages use structured
semantic markup. For example, H1 elements are used for page titles, H2, H3, and H4 elements for page sections. Menus and other link sets are placed in unordered lists. Description pages, glossaries, and this page use definition lists.
Navigation aids
- Users of text-only browsers and screen readers will note that H5 elements are used for menu titles (Primary, Secondary, Local, and Footer). JAWS users can skip to the next menu by using ALT+INSERT+5.
- The home page and certain other pages include a search form (access key 4).
Forms
- Fieldset elements, each with a Legend, are used to group related input elements. This is best demonstrated on the Advanced Search page.
- Label elements are associated with each input element. This allows screen readers to intelligently announce what a particular input element is, by reading the label. This also makes the web-based form easier to use with a mouse: clicking anywhere on the text label will place the cursor inside the text box or toggle the radio button.
- Drop-down lists are provided where there is a limited number of values for an input box.
Links
- Many links have title attributes which describe the link in greater
detail, unless the text of the link already describes the target
(such as the title of the page).
- Wherever possible, links are written to make sense out of context.
Many browsers (such as JAWS, Home Page Reader, Lynx, and Opera) can
extract the list of links on a page and allow the user to browse the
list, separately from the page.
- Except in certain cases, link text is never duplicated; two links with the same link text always point to the same address. The exceptions will be on context specific pages, such as plant versus fungi pages, and links on species pages. For example, species description pages have links called "specimens", "description", "photos", as well as links for states and counties, but in each case these links point to further information for only that species.
- There are no "
javascript:
" pseudo-links. All links can be followed in any browser, even if scripting is turned off. The current exception to this is the advanced search results page (search.xsql) which has javascript form submit links. We hope to replace these with a non-javascript method.
- There are no links that open new windows. Currently no links are planned which open new windows. This gives users the choice within their browsers to open links in the same window, a tabbed window, or a new window.
Images
- All content images include descriptive ALT attributes and most include TITLE attributes.
Purely decorative graphics include null ALT attributes.
Gallery page thumbnail and full images do not have ALT or TITLE attributes that distinguish between the images.
Visual design
This site uses cascading style sheets (CSS) for visual layout.
- For screen readers and text-only browsers, or browsers with CSS turned off, the content is presented first and "skip" links go to the menus which follow.
- This site uses both relative font sizes and a scalable page layout which are
compatible with the user-specified "text size" or "zoom" options in visual browsers.
For Internet Explorer, the limited text resizing feature ("View" menu, "Text Size"), will work but jumps in size are greater than in other modern browsers.
- The content of each page is still readable for browsers or devices that do not support stylesheets at all.
- Stylesheets are not served to old browsers, such as Netscape Navigator 4 and Internet Explorer 4, but page content remains accessible.
- Most pages use a print stylesheet to change the visual layout when printing a web page. Some content, such as menus, is then omitted.
References used for the standards and accessibility design of the vPlants site include:
- Dan Cedarholm, 2004, Web Standards Solutions: The Markup and Style Handbook, Friends of ED.
- Dan Cedarholm, 2006, Bulletproof Web Design: Improving flexibility and protecting against worst-case scenarios with XHTML and CSS, New Riders.
- Joe Clark, 2003, Building Accessible Websites, New Riders.
- Steve Krug, 2000, Don't Make Me Think! A Common Sense Approach to Web Usability, New Riders, a newer version is available.
- Mark Pilgrim, 2002, Dive Into Accessibility, online book.
- Jeffrey Zeldman, 2003, Designing with Web Standards, New Riders, a newer version is available.
Thanks also to many additional authors of web design books and online articles, including Douglas Bowman, Andy Budd, Molly Holzschlag, Joseph Lowery, Eric Meyer, Dave Shea, Charles Wyke-Smith, and the many authors at A List Apart, Sitepoint, and Wrox books.
Accessibility references
- W3 accessibility guidelines, which explains the reasons behind each guideline.
- W3 accessibility techniques, which explains how to implement each guideline.
- W3 accessibility checklist, a busy developer's guide to accessibility.
- U.S. Federal Government Section 508 accessibility guidelines.
Accessibility software and services
- Bobby, a free service to analyze web pages for compliance to accessibility guidelines.
- HTML Validator, a free service for checking that web pages conform to published HTML standards.
- Web Page Backward Compatibility Viewer, a tool for viewing your web pages without a variety of modern browser features.
- JAWS, a screen reader for Windows. A time-limited demo is available.
- Lynx, a free text-only web browser.
Related resources
- WebAIM, a non-profit organization dedicated to improving accessibility to online learning materials.
- Designing More Usable Web Sites, a large list of additional resources.