- From: Marja-Riitta Koivunen <marja@w3.org>
- Date: Wed, 03 Apr 2002 17:43:30 -0500
- To: Nick Kew <nick@webthing.com>, Laurent Denoue <Denoue@fxpal.com>
- Cc: Steven Pemberton <steven.pemberton@cwi.nl>, Jim Ley <jim@jibbering.com>, <www-annotation@w3.org>, <w3c-wai-er-ig@w3.org>, HTML WG <w3c-html-wg@w3.org>
At 07:56 PM 4/3/2002 +0100, Nick Kew wrote: >On Wed, 3 Apr 2002, Laurent Denoue wrote: > > > Based on his research, David Bargeron (followed by Ka-Ping and myself) > pointed out that > > "using 'human-level' page content as the basis for anchoring was more > effective than using the internal structure of the page". I can imagine that human-level page content pointers are may be easy to come up with some pages e.g. those that follow the form of common book, a research document, play etc. format. With these formats it is easy to define unambiguous pointers that are both intuitive for users and exact for machines. For instance, we can talk about Chapter 2 in a book or References section or the Chapter named "Architecture". However, many Web pages do not follow such commonly known human-level formats. How should we then point to them exactly and intuitively? Even these Web pages have a structure consisting of elements that come from the standard mark-up languages. This structure is often visible to users even if they are not familiar of the mark-up languages. So I don't think it is totally unintuitive to use this structure. For instance, Chapter 2 could in XPointer format refer to the second level 2 header, or Chapter with "Architecture" could refer either to the 3rd level 2 header that happens to have that name or directly refer to the the level 2 header with "Architecture" string. I do agree that there are cases, such as with the headers in HTML, where it would be easier to think that the paragraphs under each header are actually under the header also in the tree structure. Annotea uses currently the XPointers to be able to point to exact locations in the element tree structure. Using XPointer does not in anyway prevent adding more human-level content to the annotation schemas to help detect document changes. This could be done at least in two ways: 1) Currently we are not using all the capabilities of XPointer to keep it simple. There are most probably things that can be changed in our practices to make the XPointers themselves more robust and capture more human level information e.g. add some of the text from the document to the pointer. 2) It is quite possible to add more information about the selected location e.g. the selected text in addition to the XPointer. Also it is possible to add more info, such as a checksum, so that we know if the documents have been changed or not. It would be great if the Web server could give us that information. While everything is possible our initial goal with Annotea pointers was to keep it simple and as standard as possible and avoid adding data and processing that only had minor effects to the system. Right now we don't have much resources for this question. However, we are always very interested in hearing about different experiments that aim to make the XPointers in Annotea or similar applications more robust. Marja
Received on Wednesday, 3 April 2002 17:47:05 UTC