- From: Kitch Barnicle <barnicle@trace.wisc.edu>
- Date: Fri, 09 Jun 2000 13:56:30 -0500
- To: w3c-wai-ua@w3.org
- Message-Id: <4.2.2.20000609134957.00baf980@trace.wisc.edu>
Hi Everyone, This message is in response to my action item to propose a minimum requirement for checkpoint 10.5. I'm sorry about the long winded way I get there, but I tried to list all of the related issues that I could think of so that we'd have some background for our final decision. Of course, in some places I have had to make certain assumptions since, at the moment, I don't know of any usability data to back up my observations. Checkpoint 10.5 from May 7: Allow the user to configure the user agent so that the user's preferred one-step operations may be activated with a single input command (e.g., key stroke, voice command, etc.). [Priority 2] Note: User agents are not required to provide single command activation of all user agent functionalities at once, only some of them. Furthermore, in some modes of interaction (e.g., when the user is entering text), the number of single commands available will be significantly reduced. This checkpoint is an important special case of checkpoint 10.4. Background - assumptions - issues 1. Keyboard access to browsers is essential for keyboard users, including users of screen readers, magnifiers and voice browsers as well as users with mobility impairments who are unable to use a pointing device. 2. Keystroke commands, beyond simple navigation, can improve a keyboard user's browsing efficiency. 3. Single keystroke commands are particularly useful for individuals with mobility impairments who cannot, or cannot without great difficulty, activate two keys at the same time. (single finger typers, head stick users, individuals with low range of motion etc) 4. While sticky keys would allow a single finger typer to use combination keystrokes sequentially, rather than simultaneously, it would require the use of more keystrokes, and as a result delay task completion. 5. There are certain things to keep in mind when deciding which operations should be single key actions and which keystrokes should be user configurable. 6. Single stroke commands should, at a minimum, be assigned to those commands that are used most frequently. 7. Single stroke commands should also be assigned to actions that would otherwise require several keystrokes. For example, let's say there is a single keystroke command that moved the focus up, say 10 links, or to the first link on the next screen's worth of text, or as our guidelines recommend to the next structural element. Such a command could, in theory, greatly improve a user's efficiently. 8. I suspect that in the case of browsers, navigation commands are used most often, followed by document management commands such as bookmarking, cutting and pasting, and saving, followed by configuration commands such as changing colors, setting the default home page etc. 9. It was also brought to my attention that it may not only be important to allow the user to configure shortcuts for frequently used commands. A user may need to configure shortcuts in a browser for commands that are particularly difficult to use, for whatever reason, but which may not be used frequently. 10. As David pointed out on our last call, each user may have a different set of "favorite" commands, although I suspect there is a common subset of "favorite" commands that many users share. 11. The number of operations that can be assigned to a single keystroke command is limited, as far as I know, by a) the number of keys on the keyboard, b) the need to avoid conflicting with operating system commands c) the need to avoid conflicts with other browser operations, such form controls and accesskeys d) the need to keep the interface simple, for example a user could get confused if he thinks he is in text entry mode and the browser seems to be doing strange things e) the need to prevent the user from making mistakes - If there are a lot of single keystroke commands that use alphanumeric keys, users may end up accidently issuing commands. f) the need to avoid conflicts with other applications, including assistive technology - Of course, making the keystroke commands configurable may help user avoid conflicts with AT. 12.Other implementation issues a) choosing logical keys for single stroke operations b) helping the user learn about the availability of default single keystroke commands c) in the case of alphanumeric keys, letting the user know which mode he is in, if modal e) what happens when you have a media player embedded in a web page, could the browser and media player have conflicting keystroke commands 13. Configuration issues a) helping the user assign appropriate keystroke commands, b) providing technical support for those configurable short cuts - How do you help the users who says "I hit "Z" and nothing happened," when your browser doesn't have a "Z" command c) some of the same functionality can be provided by programmable keyboards. d) letting the user know the current keyboard configuration e) saving configuration settings f) letting users restore defaults. 14. After thinking about all these things, I proposed that we require a minimum set of single stroke commands but that we also include in the techniques other commands that may be useful as single stroke commands. I am not convinced that this is the best list but I figure that it is time to send it out for your input. I know that I haven't fully addressed the issue of user configurability but I need a bit more time to phrase my recommendation for that. I will try to propose something ASAP. I propose the following minimum set of commands be accessible with a single keystroke or that the user be able to configure those as single stroke commands those items on this list. 1. next link 2. previous link 3. next structural element(s) - (each structural element gets its own keystroke??) 4. back 5. forward 6. refresh 7. page up 8. page down 9. line up (arrows) 10 line down (arrows) 11. next active element Other useful commands that may be candidates for single stroke assignment 12. stop loading 13. to address bar / open location 14. next viewports 15. load/unload graphics 16. increase font size 17. decrease font size 18. page search 19. add to bookmark 20. go to bookmark list 21. go to history list 22. navigate among all Elements 23. turn on/off colors/style/sheets 24. help - for conventions sake, I think this should stay at F1 Another questions is whether we need a different set of single keystroke commands for media players? (e.g. stop, start, pause, volume) Additional Materials With the help of a student, I gathered a list of the single keystroke commands available in Internet Explorer 5.0, Opera 4.5 and Netscape 4.5. Kitch
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- text/html attachment: single_key.htm
Received on Friday, 9 June 2000 14:55:08 UTC