Liz Fuller April 26, 1999
During the 1999 CSUN conference, in the Information Curb Cuts demonstration room, members of the Trace staff demonstrated several tools that have been developed to assist screen reader users in the navigation of tables and documents in web pages. During these demonstrations, comments and observations of the attendees were recorded. This short paper will present the results of these very informal user evaluations.
There are four tools and they are available at the following web page: Designing More Uable Documents
Two of the tools are PowerToys1 created by Mark Novak, Trace Center Engineer for general document navigation. The Headers PowerToy generates a list of all the headers on a web page. The user can select a header from this list to take them to that header in the current web page. Similarly, the Links PowerToy generates a list of all the links contained within a web page. This PowerToy differs from a similar PowerToy provided by Microsoft in that in cases where images contain links, the PowerToy developed by Novak displays the alt-text rather than the URL of the link.
Another of the tools is a table navigation Javascript. This script was the proof of concept and the groundwork for the tool listed below, HelpDB. The table navigation script is a Javascript that exists on the same page as the table that is to be navigated. This script causes another web browser window to open. This new window contains the text, as well as column and row headers and cell position location information for each cell. The user can use the keyboard's arrow keys to move between cells. Novak, Jon Reinberg, and Wendy Chisholm developed the Javascript.
The final tool, HelpDB (Help Da Browser) is being developed by Novak to improve the ability of users to a) navigate web page tables and b) infer web page structure by listing all link, header, and table elements contained on a web page in their order of occurrence. This program uses Microsoft's component object model (COM) and several publicly available application program interfaces (APIs) to communicate and inter-operate with Internet Explorer version 4.0+ and above. This program works with the browser, so that when a new page is loaded it provides a list of the document headers, links and/or tables as selected by the user. Selecting a header or link from the list causes the browser to go to that item. Selecting a table from the list causes the HelpDB program to "walk" the table. The user can then navigate the table using the keyboard's arrow keys. Standard speech output reads cell contents as well as row and column headers and cell position information.
The evaluation of these tools at this point has only been through informal user testing. During the 1999 CSUN (California State University, Northridge) "Technology and Persons with Disabilities" conference sponsored by the Center on Disabilities, Trace staff demonstrated these tools to conference attendees in the Information Curb Cuts room.
The majority of visitors to the Curb Cuts room at the CSUN conference only received a demonstration of these tools. However, all of the visitors were encouraged to play with the tools and provide constructive feedback and suggestions for improving them. Those who provided such input included four people who are blind and two who are sighted.
The two most common types of suggestions that we received dealt with user options and the navigation abilities of the table navigation tools. The options that people requested included the ability to have parts of the cell information repeated and to choose to repeat either headers only, data only or both. Currently neither the HelpDB program nor the table navigation javascript provides the ability to repeat a cell without moving off the cell and then returning. People also wanted to be able to select the order of presentation of the three different types of information: data, headers, and position information. Currently, neither program includes this feature. Additionally, the ability to select the level of detail of the cell presentation was requested. Three potential options, that participants recommended, are;
Finally, the participants requested that they have the ability to select which row(s) and column(s) should be considered headers if none are marked. The HelpDB program does provide an option to enhance the table. This tells the program to use far left column and top row as headers if no headers are marked. Users appreciated this but wanted the additional ability to select themselves which row and/or column should be read as headers.
The navigational abilities that were requested include the ability to skip to either the top or bottom of the current column and to either the beginning or end of the current row. Some people also requested the ability to have the data contents of an entire row or column read via a single keystroke.
One of the questions we posed to participants asked how they prefer information about a cell's position be presented. All of the people who commented on this believed that the absolute position number that HelpDB used was not helpful. Instead, they suggested providing this information in "row #, column #" format.
We also received a few other comments. One user felt that, in the table overview provided at the beginning of the table navigation, it might be helpful to include information on blank cells and cell spanning. Another user suggested the use of a different voice font for data versus header and position info.
Finally, we received one comment on the document navigation header tools, the header list in HelpDB and the Header PowerToy. The suggestion was to indent different levels and provide hierarchical numbering instead of single level. The hierarchical numbering would be useful to all users and the indentation would be an additional help for those who can see the layout.
RecommendationsFor the table navigation tools, consider…
For the document navigation header tools consider…