Open Annotations vs Open Bookmarks

[Katong]

There lots of interesting material in www.open annotations.org. Much
to leverage I'm sure.

Below, the principles of their alpha3 data model (http://
www.openannotation.org/spec/alpha3/). Some of the more interesting
points:

- allows for multimedia annotations (and annotations of multimedia)
- everything (annotation, body of annotation, target(s)) resolves to
an HTTP URI
- fragments (ie sentences, etc) are identified using fragment URIs,
with different systems for different target data types (xhtml, pdf,
xml, etc)
- talks about dealing with offline resources - I don't quite get that
part...offline resources have a urn:UUID which servers can then
resolve to an HTTP URI. The documentation on this point is not yet
fully released. But it sounds like to could be consistent with the
urn:UUID scheme for epub metadata.

- - - cuts and pastes - - -

2. OAC Guiding Principles

1. The OAC effort focuses on interoperability for annotations across
clients, services and collections. It does not in any way prescribe
client user interface, nor internal client architecture.

2. The focus is on sharing annotations for scholarly purposes.
However, in order to maximize the likelihood of adoption, care will be
taken to make the interoperability framework readily applicable in
other domains.

3. In alignment with the prevailing view, an Annotation is a document
containing references to the Body and Target, which the Body is
somehow about.

4. Contrary to the prevailing view, in which the Body is textual,
Annotations must allow for both Body and Target of any media type.

5. Contrary to the prevailing view, in which the author of the
Annotation and the author of the Body are the same, the Annotation,
Body, and Target can have different authorship.

6. The previous principles lead to an annotation model in which all
core entities are Web resources: Annotation, Body, and Target should
all be identified with HTTP URIs where possible.

7. Many Annotations involve parts of resources (image regions, slides
of a video), and therefore support must be provided for resource
segment addressing. Preferably this should be done with URIs (eg. URI
fragments), but extensibility must be provided for cases where the use
of URIs for segment addressing is not possible.

8. A variety of more complex scholarly annotation scenarios involve
multiple Targets; the model must support this.

9. URI-addressable resources are ephemeral: the representations
obtained by dereferencing their URI may change over time. Certain
Annotations pertain to specific representations of Body and/or Target,
and therefore they risk to be misinterpreted once those
representations changed. Measures should be provided that can help in
avoiding misinterpretations of Annotations, including the expression
of timestamps and fixity information for Body and Target.

10. The annotation model should provide a set of top-level classes/
entities and properties/relationships that will maximize
interoperability across annotation clients, servers, collections and
applications – but which can be extended and refined for specialist
use cases.

11. In order to increase the likelihood of adoption, and in alignment
with the goal of sharing annotations, no client-server protocol for
publishing/updating/deleting annotations will be specified. Rather,
the specifications will take a perspective whereby clients publish
annotations to the Web and make them discoverable using common Web
approaches. Such an approach does not require a preferred annotation
server for a client, yet it does not preclude one either.

- - - end cut and paste fm http://www.openannotation.org/spec/alpha3/
- - -

If you got this far, you might be open to this idea: should we
consider open bookmarks in .epub files as one particular use case of
the open annotations effort?

The biggest hurdle for me is that we don't have a habit of
relating .epub files to URIs. Still, it's one approach. Both Google
and Open Library do link URLs (if not URI or handle) to epubs with the
latest epub being associated with a web address. For Google Books, the
URL is the main reference for the book, and the epub just a file
associated with it. Not sure if either Google or Open Library
timestamp the epub files they derive from their web resource.

[Hadrien Gardeur]

Most of these principles are great ideas, but I'll refer to the last
one: "in order to increase the likelihood of adoption, and in

alignment with the goal of sharing annotations, no client-server
protocol for publishing/updating/deleting annotations will be
specified".

From my point of view, OpenBookmarks is essentially such a protocol
and if we follow the same guidelines, we'll end up with a spec fully
compatible with the OpenAnnotation project.

I've read their spec too: while I agree with the overall model, I
believe that they shouldn't even try to define such things as fragment
URIs or annotation types to create something truly universal.

Hadrien