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 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 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.
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".
- 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?