Thanks to Jorge, who commented the blog Liferay 6 and Semantic Web. It would be better to use the message boards, instead of blog posts, as a way to share ideas, since that will allow everybody to share their ideas so that we could come up with the best design possible. Thus I posted the same using the message boards.
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Liferay 6 and Semantic Web
The Semantic Web is an evolving development of the World Wide Web in which the meaning (that is, semantics) of information and services on the web is defined, making it possible for the web to understand and satisfy the requests of people and machines to use the web content.
Liferay goes Semantic Web! See ticket: Support RDF - Semantic Web.
The portal tagging system allows us to tag web content, documents, message board threads, and more and dynamically publish assets by tags. Tags provide a way of organizing and aggregating content. Basically, the tag administration determines which tags are available for use. The users use these tags on their content. Any content that is tagged can be grouped or aggregated.
The following figure depicts an overview of tags, categories, and assets:
Abstracted from the book: Liferay Portal 6 Enterprise Intranets
Folksonomies
Folksonomies are a user-driven approach to organizing content through tags, cooperative classification, and communication through shared metadata. The portal implements folksonomies through tags. A tag may be associated with many assets, whereas an asset may have many tags associated with it. This is what we called tagging content. Also, a tag may have many properties. Each property is made up of name-value pair.
A tag may be associated with content. Using tags, you can tag almost anything: Bookmarks' entries, Blogs' entries, Wiki articles, Document Library documents, Image Gallery images, Journal articles and Message Board threads, and so on. You can also use these tags to pull content within the Asset Publisher portlet.
Taxonomies
Taxonomies are a hierarchical structure used in scientific classification schemes. Although taxonomies are common, it can be difficult to implement them. The portal implements taxonomies as "vocabularies and category tree" in order to tag contents and classify them.
You can have more than one vocabulary, which forms a top-level item of the hierarchy. Each vocabulary may have many categories. That is, a category cannot be a top-level item of the hierarchy. However, a category can have other categories as its child or siblings. Therefore, vocabulary and categories form a hierarchical tree structure.
In the same way, a category may have many properties. Each property is made up of a name and a value.
In addition, a predefined category will be applied to any asset. In a word, assets could be managed and grouped by categories.
Category Tree
It is very useful that parent categories can have multiple child categories. This parent-child relationship forms a hierarchical structure. However, categories don't have siblings, for example, left-side category and right-side category. Parent-child relationship plus left-side category and right-side category form a tree called Category Tree. This feature will come out soon.
Why it doesn't merge both kinds of tags using ontology
As you can see, there are two kinds of tags: taxonomies and folksonomies. Both of them can be used as a way of organizing and aggregating content. Folksonomy is a way of classification, creating, and managing tags to annotate and categorize content, whereas taxonomy is a hierarchical structure only for classification.
In fact, taxonomies and folksonomies are different. Taxonomies are a closed set of categories (also called tags) and the vocabulary, created and organized in a hierarchical structure. It helps standardization, especially when you store it in the Shared Global group to standardize categorization through all of the organizations. In a word, folksonomies are an open set of tags, which are extended by the end user.
Why can't we merge both of them through ontology? Ontology—the study of entities and their relations—is less concerned with what "is" than with what is possible. The answer would be "yes".
What's next?
Merge tags and categories through ontology.
RDF is a standard model for data interchange on the Web. RDF has features that facilitate data merging even if the underlying schemas differ, and it specifically supports the evolution of schemas over time without requiring all the data consumers to be changed.
RDF extends the linking structure of the Web to use URIs to name the relationship between things as well as the two ends of the link (this is usually referred to as a "triple"). Using this simple model, it allows structured and semi-structured data to be mixed, exposed, and shared across different applications.
This linking structure forms a directed, labeled graph, where the edges represent the named link between two resources, represented by the graph nodes. This graph view is the easiest possible mental model for RDF and is often used in easy-to-understand visual explanations.
See details of RDF at http://www.w3.org/RDF
Your suggestions or comments or vision?
Jonas Yuan
---------------------------
The Author of Liferay Books:
Liferay Portal 6 Enterprise Intranets
Liferay Portal 5.2 Systems Development
Liferay Portal Enterprise Intranets
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Liferay 6 and Semantic Web
The Semantic Web is an evolving development of the World Wide Web in which the meaning (that is, semantics) of information and services on the web is defined, making it possible for the web to understand and satisfy the requests of people and machines to use the web content.
Liferay goes Semantic Web! See ticket: Support RDF - Semantic Web.
The portal tagging system allows us to tag web content, documents, message board threads, and more and dynamically publish assets by tags. Tags provide a way of organizing and aggregating content. Basically, the tag administration determines which tags are available for use. The users use these tags on their content. Any content that is tagged can be grouped or aggregated.
The following figure depicts an overview of tags, categories, and assets:
Abstracted from the book: Liferay Portal 6 Enterprise Intranets
Folksonomies
Folksonomies are a user-driven approach to organizing content through tags, cooperative classification, and communication through shared metadata. The portal implements folksonomies through tags. A tag may be associated with many assets, whereas an asset may have many tags associated with it. This is what we called tagging content. Also, a tag may have many properties. Each property is made up of name-value pair.
A tag may be associated with content. Using tags, you can tag almost anything: Bookmarks' entries, Blogs' entries, Wiki articles, Document Library documents, Image Gallery images, Journal articles and Message Board threads, and so on. You can also use these tags to pull content within the Asset Publisher portlet.
Taxonomies
Taxonomies are a hierarchical structure used in scientific classification schemes. Although taxonomies are common, it can be difficult to implement them. The portal implements taxonomies as "vocabularies and category tree" in order to tag contents and classify them.
You can have more than one vocabulary, which forms a top-level item of the hierarchy. Each vocabulary may have many categories. That is, a category cannot be a top-level item of the hierarchy. However, a category can have other categories as its child or siblings. Therefore, vocabulary and categories form a hierarchical tree structure.
In the same way, a category may have many properties. Each property is made up of a name and a value.
In addition, a predefined category will be applied to any asset. In a word, assets could be managed and grouped by categories.
Category Tree
It is very useful that parent categories can have multiple child categories. This parent-child relationship forms a hierarchical structure. However, categories don't have siblings, for example, left-side category and right-side category. Parent-child relationship plus left-side category and right-side category form a tree called Category Tree. This feature will come out soon.
Why it doesn't merge both kinds of tags using ontology
As you can see, there are two kinds of tags: taxonomies and folksonomies. Both of them can be used as a way of organizing and aggregating content. Folksonomy is a way of classification, creating, and managing tags to annotate and categorize content, whereas taxonomy is a hierarchical structure only for classification.
In fact, taxonomies and folksonomies are different. Taxonomies are a closed set of categories (also called tags) and the vocabulary, created and organized in a hierarchical structure. It helps standardization, especially when you store it in the Shared Global group to standardize categorization through all of the organizations. In a word, folksonomies are an open set of tags, which are extended by the end user.
Why can't we merge both of them through ontology? Ontology—the study of entities and their relations—is less concerned with what "is" than with what is possible. The answer would be "yes".
What's next?
- Ontology support
Merge tags and categories through ontology.
- RDF - Sematic Web (Web 3.0) - support
RDF is a standard model for data interchange on the Web. RDF has features that facilitate data merging even if the underlying schemas differ, and it specifically supports the evolution of schemas over time without requiring all the data consumers to be changed.
RDF extends the linking structure of the Web to use URIs to name the relationship between things as well as the two ends of the link (this is usually referred to as a "triple"). Using this simple model, it allows structured and semi-structured data to be mixed, exposed, and shared across different applications.
This linking structure forms a directed, labeled graph, where the edges represent the named link between two resources, represented by the graph nodes. This graph view is the easiest possible mental model for RDF and is often used in easy-to-understand visual explanations.
See details of RDF at http://www.w3.org/RDF
Your suggestions or comments or vision?
Jonas Yuan
---------------------------
The Author of Liferay Books:
Liferay Portal 6 Enterprise Intranets
Liferay Portal 5.2 Systems Development
Liferay Portal Enterprise Intranets
Jorge Ferrer:
Hi Dave,Dave Weitzel:
a) DUBLIN CORE META tags - I have seen posts about this but cant see how it is implemented if at all. (that is web 1.0 I know!)
That's interesting. Do you have a more detailed proposal for how to add support for Dublin Core in Liferay?
For example:
- For which portlets (or asset types) would you apply it
- How would the dublin core information be used? Do we need to allow exporting it as XML or RDF?
- What would be the use cases for the functionality?
"Dublin Core META tags" is a bit strange term. These are known in the library community as metadata - as they are describing a resource - these are not tags. Metadata examples are title, author, date, etc..(see http://dublincore.org/documents/dcmi-terms/)
How they could be associated with a different types of resource, as an example one may check here http://dublincore.org/documents/usageguide/ and here http://dublincore.org/documents/profile-guidelines/
In general, as each term has a URI it can be easily expressed in both RDF/XML and XML (no RDF).
Metadata terms/profiles - may come from different namespaces, not only from Dublin Core .
- It could be applied for every portlet to define the portlet properties itself (e.g. portlet title, subject, creator, date, version of Liferay etc.)
-It could be applied to each resource used/produced in Liferay (web content, web page, document, image, bookmark, message etc..)
-Numerous use cases dealing with interoperability : export/import of resources in/from Liferay to other systems, showing metadata of a bookmarked resource coming from external system, could be made absolutely easier - by using standardized metadata terms to describe the resources - i.e. interoperability, knowledge discovery and sharing.. some links already were provided in this thread
-especially interesting could be the possiblity to re-use external concept vocabularies and ontologies (see as example: http://www.w3.org/2004/02/skos/ ) that could be applied to resources
-etc..
