Work on Annotation Found Elsewhere

Recently during my regular research work on annotation I came across some work done by W3C on Annotation. I was surprised to see that the work on annotation was quite active back in late 1990s.

Annotation project using RDF at W3C:

• WWW9 Developer's Day presentation
• paper submitted to UIST 2000
• RDF Description Services (discussion note for the RDF Interest Group).

some interesting work elsewhere:

• Dan Connolly's Javascript code for excerpting from the Web.
• The Crit service, based on CritLink (opensource Perl software) is one of the longest established online annotation servers.
• Netscape's What's Related service uses RDF to send 'related link' annotations to browsing clients. See also Mozilla documentation.
• USC Annotation Technology pages include a set of specifications for annotation software design and a Java implmentation, Annotator.
• Aggregating Recommendations using RDF, Libby Miller.
• NCSA Hypernews
• ComMentor: Scalable Architecture for Shared Web Annotations as a Platform for Value-Added Providers, at Stanford
• Cornell Annotation System
• Web Interactive Talk claims to be 'the first dialectical discussion system'. Here is a An Overview of 'Web Interactive Talk', the "first dialectical discussion system" (1994)
• A Protocol for Scalable Group and Public Annotations, by Daniel LaLiberte and Alan Braverman of NCSA
• Public Annotation Systems, discussion and implementation by Wayne Gramlich at Sun.

I hope you enjoy reading these links as much as I did.

Uniqueness of Entities

I was having a discussion with a friend of mine about what makes an object (entity) identifiable. The conversation started with different attributes of the object and then we got into a situation where we had to distinguish two objects who had similar attributes.

More often than not in an Enterprise System we are faced with a situation where two objects come across having similar attributes, which primarily (on a higher level) identify them. When we are faced with such situations then the only way out is to identify another attribute attached to the object which is bound to be unique. In a database application we have the primary keys generated by a sequence generator which guarantees its uniqueness. One the commonly used real-world example is Social Security Number in USA. The social security number is bound to be unique. Another unique attribute is the Credit Card number which is supposed to be unique as well.

In light to the above example the question we have is what is the unique identifier of the object. Is that something attached as as attribute to the object or it is the one which defines the object (rather the object itself). The more we think and discuss about it the more we come to a conclusion that there is no fixed rule as such. Both object being its own unique identifier or the object having an attribute which could uniquely identify it have their own pros and cons. COM uses GUID as a unique identifier for the objects created. A GUID is likely to be unique even though it is generated at many computers simultaneously and is done for years without any interruption.

I personally kind of find myself torn between the two approaches. Object being its own unique identifier has the benefits like the two objects can be identified unique even though they have no attributes to identify them. Whereas having an attribute which makes an object unique is that we can always work out a better combination (of attributes) if the current one is no longer able to gurantee the uniqueness.

I would like to hear from our readers what approach they would prefer in such scenarios and your experience as well. Hope this year brings lots of Joy, Happiness and good times to all of us.

Until Next Time... :)