Accessibility, in the context of websites, refers to the degree to which the content you add to your web site can be accessed by your audience; all of them, not just the able bodied ones and those with 20/20 vision. Accessible websites offer good support for screen readers, cater for users who browse the web without viewing graphics and who wish to magnify the text on your pages to a level comfortable for their eyesight.
Dreamweaver has a number of features which enable web developers to ensure that content on their pages Is accessible. There are useful dialogs which appear automatically when content added to a page can be made accessible. Dreamweaver also allows web page creators to check their pages for any accessibility issues.
The main settings in Dreamweaver are located by choosing Edit - Preferences. On the left of the Preferences screen there are a series of categories. In the General category, you should ensure that the option to use CSS instead of HTML tags is activated. Also, in the Accessibility category, you should switch on all of the checkboxes for displaying a dialog of relevant accessibility attributes for form object, media (Flash, video etc.) and form elements.
So what is the result of switching on these various preferences? Well, firstly, Dreamweaver will use CSS tags whenever you format text or the background of the page. The CSS tags contain the formatting information and will be placed in the head area of the page away from the content which will be in the page body. The program will also display a dialog box with accessibility options each time you insert an image, form field or media element such as a Flash movie or video clip.
Thus, whenever you add an image to a page, a dialog will appear prompting you for alternate (alt) text. This attribute makes images more accessible by providing a description of the images to users accessing the web with a slow connection as they wait for the image to load or who have disabled the display of images. The alt text will also be spoken by the screen readers commonly used by web surfers with impaired vision.
In addition to the alt text, Dreamweaver also allows you to browse for or enter a path leading to a long description file. This option relates to HTML’s longdesc attribute which should be used for images whose content is too detailed or too important to be described in the short alt text.
When the accessibility options relating to forms are active, Dreamweaver will display a dialog of options every time a form or form element is added to the page. The first set of options relates to the addition of the LABEL tag which serves to associate descriptive text labels with the form control to which they relate. The dialog also allows you to specify the order in which elements will be accessed by pressing the Tab key on the keyboard.
Similarly, if you add a media element to a page, the accessibility dialog pops up and prompts you to enter up to three elements: a title, an access key and a tab index. The title should be a description of the media element and serves a similar function as the alt text which is used with images. The access key is an optional keyboard shortcut which can be used to make the media element active. The tab index is a number which indicates the position of the element in the tab order for that page. The tab order is the order in which elements are accessed when the user presses the Tab key.
Dreamweaver not only gives you help in making your page content accessible, it will also check your pages to see if they contain elements which are not accessible. To use the accessibility utility, click on the File menu then on Check Page and finally on Accessibility. The utility runs and then displays a list of elements on the page which are not accessible. If you double-click on any of the items in the list, the code representing it will be instantly highlighted allowing you to edit it.
The writer of this article is a trainer and developer with Macresource Computer Solutions, a UK IT training company offering Adobe Dreamweaver Classes in London and throughout the UK.
October 8th, 2007
Google and IBM today announced an initiative to promote new software development methods which will help students and researchers address the challenges of internet-scale applications in the future.Â
The goal of this initiative is to improve computer science students’ knowledge of highly parallel computing practices to better address the emerging paradigm of large-scale distributed computing. IBM and Google are teaming up to provide hardware, software and services to augment university curricula and expand research horizons. With their combined resources, the companies hope to lower the financial and logistical barriers for the academic community to explore this emerging model of computing.Â
The University of Washington was the first to join the initiative. A small number of universities will also pilot the program, including Carnegie-Mellon University, Massachusetts Institute of Technology, Stanford University, the University of California at Berkeley and the University of Maryland. In the future, the program will be expanded to include additional researchers, educators and scientists.
“Google is excited to partner with IBM to provide resources which will better equip students and researchers to address today’s developing computational challenges,” said Eric Schmidt, CEO of Google. “In order to most effectively serve the long-term interests of our users, it is imperative that students are adequately equipped to harness the potential of modern computing systems and for researchers to be able to innovate ways to address emerging problems.” Â
Fundamental changes in computer architecture and increases in network capacity are encouraging software developers to take new approaches to computer-science problem solving. For web software such as search, social networking and mobile commerce to run quickly, computational tasks often need to be broken into hundreds or thousands of smaller pieces to run across many servers simultaneously. Parallel programming techniques are also used for complex scientific analysis such as gene sequencing and climate modeling.
“This project combines IBM’s historic strengths in scientific, business and secure-transaction computing with Google’s complementary expertise in Web computing and massively scaled clusters,” said Samuel J. Palmisano, chairman, president and chief executive officer, IBM. “We’re aiming to train tomorrow’s programmers to write software that can support a tidal wave of global Web growth and trillions of secure transactions every day.”
For this project, the two companies have dedicated a large cluster of several hundred computers (a combination of Google machines and IBM BladeCenter and System x servers) that is planned to grow to more than 1,600 processors. Students will access the cluster via the Internet to test their parallel programming course projects. The servers will run open source software including the Linux operating system, XEN systems virtualization and Apache’s Hadoop project, an open source implementation of Google’s published computing infrastructure, specifically MapReduce and the Google File System (GFS).
At the University of Washington, students were able to harness the power of distributed computing to produce complicated programs such as software that scans voluminous Wikipedia edits to identify spam and organizes global news articles by geographic location.
“In 2006, when I helped Christophe Bisciglia, a former UW student now a senior engineer at Google, to develop the program, our goal was to understand the challenges that universities face in teaching important new concepts such as large scale computing and develop methods to address this issue,” said Ed Lazowska, Bill & Melinda Gates Chair of Computer Science & Engineering at the University of Washington. “A year later, we’ve seen how our students have mastered many of the techniques that are critical for large scale-internet computing, benefiting our department and students.”
“Carnegie Mellon applauds Google and IBM for helping to provide the resources that will help professors better prepare our students for the challenges presented by highly parallel computing,” said Randal Bryant, Dean of the School of Computer Science at Carnegie Mellon University. “We are quite pleased to be among the first universities participating in this program this fall.”
To simplify the development of massively parallel programs Google and IBM have created the following resources:
- A cluster of processors running an open source implementation of Google’s published computing infrastructure (MapReduce and GFS from Apache’s Hadoop project)
- A Creative Commons licensed university curriculum developed by Google and the University of Washington focusing on massively parallel computing techniques available at: http://code.google.com/edu/content/parallel.html
- Open source software designed by IBM to help students develop programs for clusters running Hadoop. The software works with Eclipse, an open source development platform. The plugin is currently available at: http://lucene.apache.org/hadoop/
- Management, monitoring and dynamic resource provisioning of the cluster by IBM using IBM Tivoli systems management software
- A website to encourage collaboration among universities in the program. This will be built on Web 2.0 technologies from IBM’s Innovation Factory.
October 8th, 2007
