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Re: RDF in Annotations and Amaya

From: Sean B. Palmer <sean@mysterylights.com>
Date: Sun, 12 Nov 2000 14:34:25 -0000
Message-ID: <000a01c04cb5$ab652ce0$f765063e@z5n9x1>
To: "Aaron Swartz" <aswartz@upclink.com>, "RDF Interest" <www-rdf-interest@w3.org>
There is a whole page about RDF annotations in Amaya - in the documents
section (I just cut and pasted this, sorry for the length. Couldn't find a
URI for it!):- from C:\Program Files\Amaya\doc\amaya\Annotations.html

Annotations in Amaya
What is an Annotation?
Annotations are comments, notes, explanations, or other types of external
remarks that can be attached to a Web document or a selected part of the
document. As they are external, it is possible to annotate any Web document
independently, without needing to edit that document. From the technical
point of view, annotations are usually seen as metadata, as they give
additional information about an existing piece of data. In this project, we
use a special RDF annotation schema for describing annotations.

Annotations can be stored locally or in one or more annotation servers. When
a document is browsed, Amaya queries each of these servers, requesting the
annotations related to that document. Currently Amaya presents annotations
with pencil annotation icons (  )that are visually embedded in the document,
as shown in the figure below. If the user single-clicks on an annotation
icon, the text that was annotated is highlighted. If the user double-clicks
on this icon, the annotation text and other metadata are presented in a
separate window.

An annotation has many properties including:

Physical location: is the annotation stored in a local file system or in an
annotation server
Scope: is the annotation associated to a whole document or just to a
fragment of this document
Annotation type: 'Annotation', 'Comment', 'Query', ...
Local and remote annotations
Amaya can store annotation data in a local file system (called "local
annotations") or in the Web (called "remote annotations"). Remote
annotations are stored in annotation servers and can be downloaded and
stored by anyone having the correct access rights, such as is the case of
other HTML documents. We also refer to remote annotations as shared or
public annotations, as they can be seen by other people. If you wish to
install your own annotation server, please refer to Annotation-Server-HOWTO.

The user doesn't need a server to make local annotations. Local annotations
are stored under the user preferences directory, in a special directory
called annotations, and can be seen only by their owner (according to the
system access right setup). This directory is made of three kinds of files:

annot.index
associates URLs with the files where the metadata of the annotations are
stored.
index + random suffix
a file that stores the metadata of the annotations related to a given URL.
The metadata is specified with RDF.
annot + random suffix.html
contains the body of an annotation, stored as XHTML.
At any time, a user can convert a local annotation to a shared one, by using
the Annotations/Post annotation menu entry. If this operation is succesful,
the local annotation will be deleted, as it will have been moved to an
annotation server. The following section describes how to set up the name of
the server to which annotations should be posted.

Annotations Menu
Most of the commands needed for handling annotations can be found from the
Annotations menu shown below. The commands are explained later in this
document in the context of users' goals when handling annotations.

Configuration Settings for Annotations
The annotations configuration menu is found under theAnnotations/Configure
menu entry. The following figure shows the Windows version of this menu. The
Unix version has a slightly different user interface, but the same
functionalities.

Annotation user
A field that is associated with each new annotation as the author of the
annotation. By default, Amaya uses the login name of the user when building
the author metadata field. The annotation user setting allows a user to
change this name to a more significant one, for example, from u1723242
(which makes happy my system administrator) to marja (which other people
normally use when talking with me).
Annotation servers
This setting tells Amaya what servers it should contact when looking for
annotations. You can specify one or more servers. We use the reserved server
name localhost to tell Amaya we want to search the local annotations. It
doesn't mean we're running a local annotation server. If that were the case,
we would need to give its complete URL. Under Unix, the annotation servers
are specified as a space separated list. Under Windows, they are added one
after the other by directly typing their names in the dialog box, using the
Return key to add a new one. By default, the annotation servers field is
initialized to localhost.
TIP: If you want to temporarily disable an annotation server, add a "-" char
before its URL. Amaya will ignore it.

Autoload annotations
This setting tells Amaya whether or not to request annotations automatically
(that is, query the annotation servers ) every time that a URL is browsed.
If it's not checked, then the user has to manually invoke the Load
annotations function from the Annotations menu. Note that the if you check
this option, there may be a delay when Amaya resolves the DNS name of the
annotation servers. By default, this option is turned off.
Annotion post server
This setting defines the server to which the annotations are posted. Local
annotations are always saved to the local repository, regardless of the
value of this setting. By default, this setting is empty. Note that the post
server is not automatically included in the list of servers to be queried;
you must enter the post server name in both places, in whatever order you
choose.

Creating an Annotation
This version of Amaya support two kinds of annotations: annotations that
apply to a whole document and annotations that apply to a specific point or
selection in a document.

To annotate a whole document, just select the Annotations/Annotate document
menu entry. To annotate a point, put the caret in any point in the document
and select the Annotations/Annotate selection menu entry. To annotate a
selection, make a selection in the document, and then use the
Annotations/Annotate selection menu entry. In all of these cases, an
annotation window will appear (see following figure). The content of this
window shows the metadata of the annotation, inside a box, and the body of
the annotation.

Currently, the metadata consists of the author's name, the title of the
annotated document, the type of the annotation, the date of creation, and
the date of the last modification . Some of the metadata fields have special
properties. The source document field is also a link that points back to the
annotated text. If the user double-clicks on it, as when following any other
link with Amaya, the annotated document will be raised and the annotated
text will be highlighted. The annotation types field allows the user to
classify the annotation and change its type. Double-click on the text
"annotation type" to see the list of types available. We'll describe later
how users can also define their own annotation types. Finally, the Last
modified field is updated automatically each time that an annotation is
saved.

Below the header area is the annotation body area. It shows the current
content, and it can be edited as if we were editing any other HTML
document,. N.B., we don't support yet the use of images inside the body.
Some of the features may not be ready in the initial release, such as the
Structure view.

Saving an annotation is equivalent to saving any other document with Amaya.
The user just needs to select the File/Save command (or use its equivalent
shortcut or button menu). Local annotations are saved to the annotations
directory and remote annotations are saved to the annotation post server
where they are stored if the user has write access. To convert a local
annotation into a shared one, the user needs to use the Annotations/Post
annotation command and the annotation will be saved to the Post server as
defined in the configuration menu. If this operation is succesful, the local
annotation will be removed and further save operations will go directly to
that annotation server. In the initial release, Amaya does not support an
operation to save a copy of a remote annotation in the local annotations
directory.

Some commands applied to the document in the Amaya Document window will be
applied to annotation document in the Annotation window. For instance, the
body of an annotation can be printed with File/Print command, or reloaded
with File/Reload document command. (Note: some of these may not be
implemented yet.)

Deleting an Annotation
The Annotations/Delete annotation menu command lets you delete an
annotation. You can invoke this command from an open annotation window. You
can also delete an annotation from the annotated document by first selecting
the annotation by doing a simple click on the annotation icon, and then
calling this menu command.

Loading and Presenting Annotations
The Load annotations command tells amaya to load the annotations that are
associated to the URL of the document that is being browsed in that window.
Amaya will query the annotations servers, as set up in the
Annotations/Configure dialogue, asking for any relevant annotation.

The annotations can also be loaded automatically whenever a new page is
loaded by selecting the Autoload annotations checkbox in the
Annotations/Configure dialogue.

Note that in this version of Amaya, querying an annotation server will
return all the the annotations that are associated to to a document. In a
future version, it may be possible to use a customized query menu to refine
the query string that is sent to the servers.

The Annotations/Local filter menu allows a user to show or hide the
annotation icons from the document window, for example, to concentrate on
those that really interest him, or, to make it easier to read a heavily
annotated document. The user can show or hide annotations by three types of
metadata: by the name of the annotation's author, by the type of annotation,
and by the annotation server name. To apply any of these filters, you need
to click on the text box to select a given type of annotations, and then on
the corresponding action button. The Show all and Hide all commands apply to
all the annotations.A small and uncomfortable prefix charater shows the
status of a given entry. This character can be either a space (' '), a star
('*') or a signet ('-') to say that tje annotations belonging to this given
entrty are all visible, all hidden, or partially visible, respectively.

Note that the filter menus only show you the annotations it knows about at
the moment of its invocation. If you add new annotations in the meantime,
you'll need to destroy this menu and invoke it again to see them.

Note that for each annotation, the annotation user is shown by concatenating
the author's name to the name of the annotation server where the annotation
is stored, as shown in the following figure.

Navigating Annotations
Annotations appear as links in the Link window whih can be activated by the
Views/ Show links command. Annotations in this window are marked with the
same pencil icon as the annotations in the document window. The Link window
shows all the annotations, without taking into account whether they have
been hidden with the Annotation Local Filter menu. As with the document
window, a single-click on the annotation will select the annotated text in
the document window and a double click will open the annotation. This is an
example of how to navigate from one annotation link to another even if the
annotation cannot be seen by the user because of disabilities or because of
the characteristics of the used device.

Issues with Annotations and Modified Documents
If you are using annotations with live documents (documents whose contents
can be modified), you may encounter two kinds of problems: orphan
annotations and misleading annotations. Let's first describe a bit more in
detail how Amaya attaches annotations to documents.

Amaya uses XPointer to describe where an annotation should be attached to a
document. XPointers are based in the structure of the document. To build an
XPointer, for example for a selection, we start from the first point of the
selection and walk backwards through the document's structure, until we find
the root of the document. If an element has an ID attribute, we stop
building the XPointer and we consider that the beginning of this XPointer is
the element that has this ID attribute value. For example,. if you look at
the HTML source for this document, you'll notice that this section (Issues
with annotations...) is enclosed within a DIV element that has an ID
attribute with the value "Issues". Here's an extract of the source code:

  <div id="Issues">
  <h3>>Issues with ....</h3>>
  <p>If you are using...</p>
  <p>Amaya uses <strong>XPointer</strong>...</p>
  ...
  </div>
And here's the XPointer that points to the second paragraph::

xpointer(id("Issues")/p[2])

The above XPointer points to the second p element, from the element parent
having an ID attribute with value "Issues". (In order to select a whole
paragraph, we put the cursor in the paragraph and pressed the Escape (Unix)
or F2 (Windows) key). Note that the use of the ID attribute allows the
document author to move this whole section elsewhere on the document,
without needing to update the XPointer. The XPointer doesn't depend on the
elements that precede this particular DIV element.

We say that an annotation becomes an orphan when it cannot be attached
anymore to a document, that is, when the XPointer doesn't resolve anymore to
any element in the strucutre. This happens when a document's structure is
modified. For example, the above XPointer wouldn't resolve anymore if we
destroyed the ID attribute "Issues". Amaya will warn you if it detects any
orphan annotation while downloading a set of annotations from an annotation
server. All orphan annotations are visible from the Links view and are
associated with an icon that shows a question mark superimposed on the
annotation pencil .

We say that an annotation is misleading when it points to a wrong piece of
information. Coming back to our example, we can create a misleading
annotation if we exchange the first and second paragraph. The XPointer will
continue to point to the second paragraph, although we would have liked it
to point now to the first paragraph. This problem is even more common when
you annotate a portion of text that may change. In the first release, Amaya
does not warn the user if an annotation is misleading. A future release may
notify users of the potential for an annotation to be misleading.

How can you protect yourself?

If you're the author of a document, try to use the ID attribute in strategic
places, for example, in the DIV elements. Amaya allows you to automatically
associate or remove an ID attribute to/from a set of elements by means of
the Special/Make Add/Remove ID menu command. In the above example, we could
have avoided the problem of misleading annotations if we had added an ID
attribute to the second paragraph:

  <p id="Amaya">Amaya uses...</p>
An XPointer that points to this paragraph is

xpointer(id("Amaya"))

Thus, the Xpointer will point to the same paragraph, regardless of its
position in the document's structure.

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<hr />

See also:-
http://lists.w3.org/Archives/Public/sw99/2000AprJun/0018.html
http://lists.w3.org/Archives/Public/www-annotation/2000JanJun/0006.html
http://lists.w3.org/Archives/Public/www-amaya/2000OctDec/0069.html

Kindest Regards,
Sean B. Palmer
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Received on Sunday, 12 November 2000 09:34:38 GMT

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