Re: about CritLink and annotation systems in general

Jon Garfunkel wrote:

> * glossary-style: the anchor is a phrase.
> * pointer-based: the anchor is the position within a specific document.
> * document-based: the anchor is the document itself.
>

in your document (http://look.boston.ma.us/garf/webdev/annote/software.html),
you say that CritLink and Yawas
work with pointer, page and pointer.
Crit and Yaws use String Matching, which can also be done with a XML XPointer
(using the STRING(...) operator).
In Yawas, I don't use the structure of the document to "navigate" it and find
the anchor point. Crit does the same.
To avoid the problem of multiple string matches, Yawas checks that the selection
is unique in the document. If not, it
refuses to create the annotation and asks the user to extend the selection. In a
new version, I'll try to overcome this problem
by automatically extending the selection, although the original selection will
be highlighted in the page, not the extended one.

Nobody talks about the problems involved with a proxy (local, remote or like
Crit "mediator").
They all have one problem in common : they may not work with Web pages
containing Java applets which
need to read/write data from/to their original server.
I don't know if this can be fixed, but I don't see how. Any comments would be
appreciated.

Also, please note that Crit doens't work with FRAMES.

A last problem which Crit is that it MODIFIES THE URL. You don't have this
problem with other proxy-based programs.

I really think that the client-side architecture is the best one. Of course, it
may not work with all existing browsers, since
it requires a different implementation in each one. But look at the advantages :

- you don't have to update your parser to handle annotations on new formats
(HTML... , XML, others ?)
- you don't duplicate any data, which is the case with proxy-based (local or
remote) and mediators if you want a fast
implementation
- you can annotate local pages (it's also possible with local proxy, but not
with Crit nor remote proxies)

Of course, 3V is bound to windows and IExplorer (I don't think a version for
Navigator will show up fast !).
But the biggest problem is that it works with a central, CONTROLLED server (like
CritLink).
Someone wrote that Crit doens't have this problem : of course it does. Your
annotations are stored on the Crit Server,
and the administrator can modify or filter your annotations ! It is the same as
3V.

To me, an annotation is the possibility to attach metadata to a sub part of a
Web page.
There is already a way to annotate the Web : you just write a web page with
links to the pages you want to annotate.
BUT you can only annotate the whole page. To me, an annotation can be more
precise.
BUT XPointers can handle this, so you are NOW (in theory) able to annotate any
Web Page.

Laurent.

Received on Monday, 30 August 1999 04:08:40 UTC