This article is also available in Spanish .
Personal digital assistants (PDAs) are small handheld computers, also known as palmtops, handheld PCs, or handhelds. PDAs are becoming increasingly popular, not solely for business and personal use but also for use in education. At all educational levels, PDAs are being used in the classroom for increasing students' organization, fostering collaboration, and maximizing portability of technology.
PDAs are well suited to these tasks. There are thousands of applications available, many of them free, that support a full spectrum of activities and academic disciplines. PDAs are also fiscally appealing to educational entities; most models are much cheaper than desktop computers.
In May 2001, The University of South Dakota (USD) became the first U.S. postsecondary institution to require the use of handheld computers by undergraduate students.
In many ways, PDAs provide benefits to individuals with disabilities. For example, people with learning disabilities or cognitive disabilities can benefit from PDAs' organizational and task management functions. Also, some people with mobility impairments can benefit from PDAs' small size, light weight, and portability. These latter characteristics have led vendors of augmentative communication devices to develop PDA-based aug-com products, such as the Enkidu Palmtop Impact  and the Saltillo ChatPC series .
Despite these benefits, however, PDAs are currently not accessible to all users. Users generally interface with a PDA using a small stylus for input and a small screen for output. These devices are not accessible to individuals who are unable to use the stylus or who are unable to see the screen. A growing number of assistive technologies are available for PDAs, but these technologies are often developed for only one of the major operating systems (Palm OS or Microsoft PocketPC), not both. Also, due to limitations of memory and processing power, most PDA applications tend to be minimally featured compared to their desktop counterparts, usually at the expense of accessibility. For example, PDA operating systems have minimal or no built-in support for users who need larger fonts or alternate color schemes (though some solutions have emerged from third-party developers). Also, none of the PDA versions of major multimedia players currently supports closed captions.
For blind users, choices are beginning to emerge that allow access to PDAs using speech and/or Braille output. For example, Dolphin Pocket Hal  is a full-fledged screen reader that runs on PocketPC devices. Freedom Scientific's PAC Mate  product line also provides access to the PocketPC operating system, though it is a self-contained device, whereas the Dolphin product actually runs on standard over-the-counter PocketPC devices. There are currently no comparable products available for Palm OS. Other compact personal information managers are available, such as the Parrot Voice Mate  and Pulse Data's BrailleNote and VoiceNote  product lines. These products, however, don't provide full access to the features and functionality of mainstream PDA operating systems and would not suffice as an accommodation for a student who is required to use a specific PDA application.
Speech recognition and text-to-speech may ultimately be a viable solution for people who are blind, as well as other individuals who are unable to use either the stylus or an attached keyboard. Current speech input/output products for PDAs include Microsoft Voice Command  and IBM Embedded Via-Voice . Both of these products, however, is command-based and does not support dictation or application-specific functionality beyond a basic core set of popular applications. Thus, their usefulness as an assistive technology is currently limited but is likely to improve, driven not by accessibility concerns but by the demands of an increasingly mobile global workforce (a good example of universal design).
The TechDis Accessibility Database Team at the University of Sussex has conducted extensive research on PDA assistive technologies and PDA accessibility. Their website Usability and Accessibility of PDAs in Education  reviews and provides links to many of the available assistive technology tools and describes current accessibility problems and solutions for specific PDA tasks and specific disabilities.
Additional information is available at the accessibility pages for the leading PDA operating system vendors:
-  available in Spanish
-  Enkidu Palmtop Impact
-  Saltillo ChatPC series
-  Dolphin Pocket Hal
-  PAC Mate
-  Parrot Voice Mate
-  BrailleNote and VoiceNote
-  Microsoft Voice Command
-  IBM Embedded Via-Voice
-  Usability and Accessibility of PDAs in Education