This is the second in a series of articles about accessibility and office documents. This article continues the discussion on the use of standard office documents such as word processor documents, spreadsheets and presentational applications. In the articles that follow, we’ll discuss the usage of Adobe Acrobat Portable Document Format (PDF) files, web site development, web applications and accessibility.
Spreadsheets are commonly used in office environments to organize large amounts of tabled data. The chief feature of the spreadsheet is its capacity to perform various calculation functions on the data and to sort and distribute the data in a variety of ways. Modern spreadsheets also have the capacity to convert tabled data into graphic representations (charts and graphs) that can also be extracted and moved to other types of office documents.
The accessibility of spreadsheets is a complex issue and depends on a number of factors. As spreadsheets are essentially tools, you first must decide if the document is intended for use as a "working document" - one that is being shared between and among a group of users with the intention of editing and redrafting - or one designed as a final product that intended for sharing without the option of changing the data. In the first case this might mean an office intranet setting where the document is shared among a group of co-workers. In the second case, the document is a final report prepared for distribution to the public.
In the "working document" situation, there would be an expectation that the users have access to the spreadsheet application to view and manipulate the data and are fluent with how the application is used. Within this context there may be some inherent accessibility issues depending upon the layout of the data set. Care should be taken to label the various columns and rows to assist all users in identifying the data. Perhaps the biggest problem for users accessing the spreadsheet with a screen reader is "orphaned" data - that is data located off in some remote area of the spreadsheet.
When spreadsheets are to be used to create documents in a final form for public use, it is most often converted into another format (e.g., placed as a table in a word processor document, or converted to Adobe Acrobat PDF or HTML form). In these cases, care must be taken to ensure that the columns and rows are labeled clearly and understandably and "tagged" appropriately (we’ll discuss tagging for PDF and HTML documents in a later article). It should be noted that converting spreadsheet data into alternate forms usually requires an extensive amount of time and testing. Occasionally, tabled information can be very complex and despite the required tagging, may still prove to be very confusing to all users but particularly for people using screen readers and other assistive technology. It should be remembered that tables are intended to support what is written in the document and should not be presented separately from the main document. That said, authors of documents containing large data sets should take care to ensure their descriptive text is understandable to the largest possible audience.
Presentational documents have become very popular in training programs as a colorful means of supporting the speakers’ comments and providing a graphical backdrop to live presentations. The most popular application in this class of office applications, Microsoft PowerPoint has become perhaps the most widely used and its name as invaded the lexicon to become the generic term for presentational documents.
In its intended format - a learning experience where the PowerPoint "slides" are projected onto a large screen or monitor - the content would obviously be inaccessible to persons with limited vision or blindness. In many of these learning situations, the presenter provides the learners with a paper copy of the "slides" as a handout. But again, in this modality, the information presented will be by and large inaccessible to persons with visual impairments and blindness. However, presentational documents are increasingly being provided to the learners in a digital format that they can view on their own computers either in real time or available for download after the live presentation. It is in this digital format that we will discuss accessibility issues.
For the purposes of accessibility, the digital version of a PowerPoint presentation should meet all of the same guidelines as a word processed documents as discussed in the previous article. Since images often make up a large part of most presentations, care must be taken to ensure that adequate alternative descriptions are used for all graphics in the presentation. In most cases these images are what I like to call "pretty pictures," simple images that decorate or "dress up" a presentation. All of these images need to be given the alternate (ALT) description.
I have provided this link to a screencast demonstrating how to add ALT text to MS PowerPoint 2007.
The steps for adding ALT text to an image in MS PowerPoint 2007 are as follows:
Those familiar with HTML code know about the Alternate attribute in the image tag, the so called ALT Attribute, and the use of the "null" or "empty" ALT attribute when dealing with non-essential images (this will be discussed in more detail in a later article). It should be noted that unlike coding HTML, there is no "null" version in these applications. Therefore care must be taken to provide a brief and succinct description.
The use of presentational documents independent of a presentation can often be confusing. The MS PowerPoint application allows for the addition of "speaker notes" in text form or recorded as an aural Narration to the document. While this latter method may seem to be the most natural and easy to accomplish, it presents an accessibility challenge to users with hearing disabilities. Thus the "speaker notes" in text form is the most accessible way to provide this feature.
Charts and graphs present a unique challenge to those creating accessible documents of any type. As these features are generally considered to be "visual aids" they may represent problems for users with visual disabilities who rely on screen readers and other assistive technology.
As a general rule, information shared in chart or graph form should always be done to supplement and support the content provided in written form. In other words, charts and graphs should not be provided independently of the written report or document and care needs to be taken to explain fully, in written form, that information which is contained in the graphic.
If a chart or graph is used in a working spreadsheet document made with Microsoft Excel 2007 you may still create ALT text for the chart using the following steps:
I have provided this link to a screencast demonstrating how this is done in MS Excel 2007.
When charts, tables and graphs are presented in presentational documents, the graphic should also be made accessible using the description above for inserting ALT text for images.
Maine CITE provides additional resources that can help you with your goal of creating accessible documents. http://www.mainecite.org/awd/accdocs.html
John Brandt is a web designer and consultant who works with the Maine CITE Program in the area of accessibility and universal design. He may be reached at firstname.lastname@example.org
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