- From: Ian Jacobs <ij@w3.org>
- Date: Fri, 07 Jul 2000 19:51:43 -0400
- To: Harvey Bingham <hbingham@ACM.org>
- CC: w3c-wai-ua@w3.org
Harvey Bingham wrote: > > National Information Standards Organization > Digital Talking Book Standards Committee > Document Navigation Features List > Status of this Document: This document is in draft status. Please send any > comments to Michael Moodie at mmoo@loc.gov. > Draft 4 -- December 29, 1999 > > Extract pertinent to our recent discussions. Thanks for this information Harvey! I would note that the navigation techniques already appear in the Techniques Document [1] under checkpoint 7.6.(though they have been edited down). - Ian [1] http://www.w3.org/WAI/UA/WD-UAAG10-TECHS-20000610/#gl-navigation > http://www.loc.gov/nls/niso/navigation.htm > > 1. Basic Navigation > Many of the navigation features which should be available in a digital > talking book of the advanced variety will of necessity correspond to the > navigation features available in today's personal computers. Blind people > who are sophisticated users of screen access technology, word processors, > or book reading software have already been exposed to many of the > navigation features discussed here. Moreover, for purposes of discussion, > it is assumed that users of the advanced digital talking book text > navigation features possess a high degree of technological sophistication. > > 1.1 Basic Movement Through Text > The advanced digital talking book should provide the ability for the user > to move through text one character, word, line, sentence, paragraph, or > page (corresponding to the printed page, if present) at a time. In > addition, the user should be able to jump to a specific page in the book > (e.g., go to print page 55) and any specific line or paragraph on that page. > The user should be able to read the entire publication--from beginning to > end--without having to jump up and down a hierarchical tree structure > (e.g., moving in and out of the Table of Contents to go to the next chapter). > Another basic movement function that needs to be provided is time. The user > should be able to move back and forth through the book using either a small > (ten seconds, for example) or a large (e.g., ten minutes) time slice > specified by the user. > > 1.2 More Sophisticated Movement > The user needs to have the ability to "jump" to specific chapters, > sections, headings, and other segments of the digital talking book. For > example, there should be functions such as "Go to next chapter," "Go to > next subheading," "Go to next section," "Go to Chapter 5, Section 1," etc. > This feature may be linked to a hierarchical, collapsible "Navigation > Control Center" (discussed later), but then again, the user should have the > ability to jump to a specific part of the book if its number or title is > already known. > > 2. Fast Forward and Fast Reverse > It would be useful to have a simple tape-recorder-type navigation feature > (cue and review function). For example, there could be a slider-like > control or push buttons that would allow the user to fast-forward or > fast-reverse through the book at a high speed. As the text was traversed, > speech could be generated at a high speed using some form of time scale > modification. Readers can learn much about the structure of the text that > is passing. For example, lists can be detected as a series of short, > staccato bursts. Paragraphs, chapter headings, etc. could be indicated by > strategically-generated tones. Thus, an individual could just zip forward > or backward through the book rather than typing commands to accomplish the > same tasks. For some individuals, this interface would be much simpler and > easier to use. It might also be much more useful in a document that is long > and does not have particularly good titling or sectioning. > An alternative method of allowing the user to skim a document would be to > have the playback device read the types of text elements that are passed. > For example, the user might hear, "part, chapter, section, paragraph, > paragraph,..., section, paragraph, paragraph,..., table, paragraph, > paragraph,..., sidebar, etc." > It is recommended that the fast forward and reverse feature allow the book > to be traversed anywhere from 10-25 times the normal or real-time reading > speed. > > 3. Reading at Variable Speeds > It should be possible to read the digital talking book at speeds that are > faster than or slower than the normal listening rate. This variable speed > feature is necessary to enable playback at a speed that is comfortable and > efficient for a wide range of readers. Three times the normal "real-time" > rate should be possible, and the slowest speed should be around 1/3 the > real-time reading rate. > The device should offer the user the option of "Time-Scale Modification" > (TSM), that is, the capability to maintain constant pitch while the > playback speed is varied. This feature should be optional, however, so that > the user can choose to have the pitch change as the playback speed changes. > The TSM system should not produce audible chopping, burble, or > reverberation and should not skip over significant units of sound at high > playback speeds. > > Regards/Harvey Bingham -- Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs Tel: +1 831 457-2842 Cell: +1 917 450-8783
Received on Friday, 7 July 2000 19:51:59 UTC