Archive for the 'OSF Web Services' Category

Schema.org: Forcing the Emergence of a New Web Paradigm

schema-org1Sometime this week I was reading a blog post that was giving some statistics related to Schema.org‘s usage on the Web. It states:

36.6 percent of Google's search results include "at least one snippet with information derived from Schema.org."

 

only about 0.3 percent of domains are using the markup code on their websites.

Someone may be surprise to see how that little number of domains produces that much snippet uses in Google searches. But this is not what interest me in this blog post. What I am interested in is that considering that 36.6% of the Google search appears to be returning structured information that uses Schema.org microdata, why is there only 0.3 percent of the domains that are using the markup?

Introduction of a new paradigm on the Web

I think that what is happening at the moment is the emergence of a new paradigm on the Web: publication of structured data. Some may say that this is happening for a long time1 and I agree with them. However, what is happening is that this structured data starts to emerge to the end users. This is not something that happened until recently (the last year or so).

What the major search engines, which participate to Schema.org, are doing is to push (to force?) this new paradigm to emerge. The thing is that to my experience the management of structured data to be published on the Web needs a different set of concepts, minding, terminology, specifications and more importantly tools.

It is true that current tools and techniques can be used to publish Schema.org markup in HTML Web pages, but to me, they are sub-optimal for the task at hands. This is probably one of the reasons why the authors of this blog posts stated:

Not surprisingly, the study also found that "larger sites" are more likely to use Schema markup. There's no definition given in the study on what makes a site big or small, but this has long been one of the concerns about Schema.org – whether small businesses/websites would have the technical chops to take advantage of the rich snippet opportunity, or if that would be left to bigger companies with more skilled webmasters and more organized online marketing efforts.

I tend to agree with that. However, this shouldn’t be the case. I think that the reason for that is that people doesn’t tend to use the proper frameworks (CMS, programming API, etc.) and data management systems that are optimized for that task. Another reason is that there is no widespread understanding and adoption of the new underlying concepts, technologies and techniques that are emerging with this new paradigm.

Coping with the evolution of Schema.org

One of the core concept introduced by this new paradigm is the Open World Assumption. This assumption basically means that we don’t know if something exists or not, if something is true or not, until it is explicitly stated. This means that it is not because we (our systems) doesn’t have some information, that this information doesn’t exists.

This is really important to understand, and this assumption has a dramatic impact on how we develop the systems that will publish this structured information on the Web. On the Web, there is no one system that has complete control over the information that may exists. Major search engines such as Google have this Open World Assumption at the core of their system. It is why they are pushing initiatives such as Schema.org, of their Knowledge Graph. Because this is how they can try to cope with the constantly evolving Web.

How does this relate to Schema.org?

Right now, there is 585 types and 807 properties in schema.org2. and there are even ways to extend the vocabulary.What that means is that this vocabulary is constantly evolving, changing, improving and increasing. If the vocabularies (ontologies) changes that often, it means that the data may should as well. However, the way most of the data management systems are currently used to publish content on the Web (mostly relational databases) can hardly cope with these kind of changes in the data, and its structure.

This is the reason why I am stating that new concepts, techniques, technologies, methods and tools needs to be used in order to be able to cope with these constant changes.

With traditional (relational) systems, every time someone would want to add new micro-data in their webpage, they would have to do an analysis of their relational data, and then to map it to different Schema.org types and properties, and then to create all the code to perform this linkage, and generate the enhanced HTML code which includes the Schema.org micro data.

Then once this is done, what happens if the vocabulary changed? If the data to publish changed? Well, all this analysis and work will need to be done again to reflect the changes in the vocabulary and the data.

However, what if a different set of concepts, techniques and tools are used to publish structured content on the Web?

What I am proposing here is a system, a framework, that manipulate entities as its core: things that are described with attributes and values. Then, these entities descriptions are carried around within your code. The logic required to handle the use case I outlined above is embedded into the ontologies, the system, the framework, the API… The only thing a developer should need to do is to care about its code and the functionalities of the system.

In such an information system, all the entities are described using internal and external ontologies. All these ontologies concepts (types and properties) need to be linked to the ones of Schema.org (or any other sources of information). Every time something change, the changes should be reflected, accounted for, into these ontologies, not into the code, the templates, or whatever. It need be transparent to the developers.

In the next section, I will show you how this can be done using the Open Semantic Framework (OSF). However keep in mind that what I am discussing in this blog post is much more general than that, and can be implemented using different tools. I used the Schema.org example, but the same minding can be applied to lot of different use cases.

Care about the code, not the data

To make my point, I will demonstrate how publishing Schema.org microdata in a Web portal can be done using a new set of techniques, concepts and tools.

The initial goal is to split the concerns: ontologists should care about the ontologies and their linkage, and developers should care about the code and the functionalities of the system. The best way to make sure that a developer cares about the code, is to abstract this complexity of the Open World Assumption behind a programming API. In this example, we will demonstrate that using the OSF PHP API.

Such a API should use the resources provided by the framework to determine if the properties and types that are used to describe a given entity can be expressed/serialized in Schema.org microdata. All this mechanic should be hidden the the developer, and should be driven by the ontologies.

This is the crux of the matter. We want to manage this complexity where it is much easier to manage: at the level of the ontologies 3. These Ontologies Driven Applications (in this case, the Ontologies Driven Frameworks or Systems) will abstract this complexity to the developers.

Let’s take this PHP [nearly pseudo] code as an example. It uses the OSF PHP API to retrieve information about an entity from a OSF Web Services instance by querying the CRUD: Read web service endpoint. Then it uses the Subject class to determine if the property(ies) and type(s) of the entity can be serialized in Schema.org microdata. In this example, the Subject class is using non-existing function calls. The goal is to show how such a basic programming API can abstract all the complexity of an evolving Schema.org vocabulary.

Let’s take that pseudo PHP code:

<?php

  // Specify the unique identifier (URI) of the entity
  $entityIdentifier = 'http://foo.com/datasets/movies/Avatar';

  // Use the CRUD: Read web service endpoint to get the
  // description of the record from OSF
  $crudRead = CrudRead();

  $crudRead->uri($entityIdentifier)
           ->send();

  $resultset = $crudRead->getResultset();

  // Get the entity (instance of the class Subject) from the resultset
  $entity = $resultset->getSubject($entityIdentifier);

  // Get the first type of the entity
  $type = current($entity->getTypes());

  // Get the name of the entity
  $name = $entity->getPrefLabel();

  // Get the genre of the entity
  $genre = $entity->getDataAttribute('http://purl.org/ontology/movies#genre');

  // Get the director of the entity
  $director = $entity->getDataAttribute('http://purl.org/ontology/movies#director');
 
  // Then run this template to generate the HTML which will embed,
  // or not, some Schema.org microdata
?>

<div <? print $type->serializeMicroformat(); ?>>
  <h1 <? print $name->serializeMicroformat(); ?>><? $name->getValue() ?></h1>
  <span>Director: <? print $director->serializeMicroformat(); ?>><? $director->getValue() ?></span> (born August 16, 1954)</span>
  <span <? print $genre->serializeMicroformat(); ?>><? $genre->getValue() ?></span>
</div>

What this template does, is to generate the HTML code, enhanced with Schema.org microdata. The serializeMicroformat($format) function does:

  1. Get the URI reference of the type/property
  2. Query the ontology to check if the type/propertyis linked to a Schema.org concept
    1. If it is not, then an empty string is returned
    2. If it is, then it serializes the micro data to add to the HTML and return it

It is as simple as that. All the “complexity”, all the work, is done at the level of the reference structure (the ontology). The result would be something like:

<div itemscope itemtype ="http://schema.org/Movie">
  <h1 itemprop="name">Avatar</h1>
  <span>Director: <span itemprop="director">James Cameron</span> (born August 16, 1954)</span>
  <span itemprop="genre">Science fiction</span>
</div>

Here is another example that does exactly the same, but that produces RDFa Lite markup:

<div vocab="http://schema.org/" <? print $type->serializeRDFaLite(); ?>>
  <h1 <? print $name->serializeRDFaLite(); ?>><? $name->getValue() ?></h1>
  <span>Director: <? print $director->serializeRDFaLite(); ?>><? $director->getValue() ?></span> (born August 16, 1954)</span>
  <span <? print $genre->serializeRDFaLite(); ?>><? $genre->getValue() ?></span>
</div>

This would produces that HTML code with RDFa Lite embedded:

<div itemscope typeof="Movie">
  <h1 property="name">Avatar</h1>
  <span>Director: <span property="director">James Cameron</span> (born August 16, 1954)</span>
  <span property="genre">Science fiction</span>
</div>

What happens there is that the API uses the Ontology (which is linked to Schema.org concepts) to determine if the entity can be rendered in Schema.org microdata. What it does is to check if the type used to describe the entity we retrieved from OSF is linked to a Schema.org concept. If it is, then the API get that reference to Schema.org, and properly serialize the Schema.org microdata snippet. The only thing the developer need to do, is to properly use the API functions. Nothing else need to be determined by him, the system will take care of the rest.

The beauty of this is that you don’t have to worry about any kind of mapping between the vocabulary (ontology) you use for describing your entities, and the Schema.org types and properties. The only thing you have to do is to re-use such a mapping with your ontologies. The PHP API will take care to produce the proper Schema.org microdata, only if the linkage exists between the content you are publishing and the schema.org vocabulary. The only thing you have to worry about is to use the API when you create your code to publish your content on the Web.

Is this vision possible? The platform that manipulates entities that way is already existing: it is the Open Semantic Framework. Everything you manipulate are such entities descriptions. Then you have the PHP API available to query the web services to get the descriptions of your entities. The only missing piece is the glue that map your entities’ types and properties to the schema.org vocabulary.

The good news is that this glue already exists, but will greatly improve in the coming months. We are currently working on a completely new version of UMBEL (Upper Mapping and Binding Exchange Layer) that will include, amongst other things, a fully updated Schema.org mapping between UMBEL and Schema.org. Note that UMBEL and its linkages is meant to be that reference structure to be used in the code I outlined above.

Conclusion

A new Web paradigm is being pushed, is being forced, by the major search engines. However, the issue that is emerging is that the current systems that are used by 98%4 of the people are not geared toward that kind of data management and these new development concepts and techniques. If this paradigm shift continues, then it will force developers to adopt completely new platforms, which rely on new technologies, concepts and specifications such as the Open Semantic Framework. The way people of that field are working will change quite significantly.

This blog post focused on the Web, and companies that are publishing content on the Web. However, to my experience with multiple different kind of organizations (municipalities, governments, Fortune 500 companies, etc.) are now experiencing the influences of the Open World Assumption in what they thought to be a Closed World. The data they are using to give different kind of services, changes, evolves. New acquisitions and new projects challenge their Close World Assumption. These changes have dramatic impacts on their infrastructure, their data and their ability to evolve and adapt to the constantly (fast) changing World .

The leap is big since the minding is quite different, investments will be required in terms of software and data migration and training of the staff. But in my view, it is essential, things are changing and organizations will need to adapt.

To conclude, how many time in a day can I read blog posts, tweets and forums where naysayers state that the Semantic Web never worked, never existed and it is doomed to be used by academicians only? Multiple… but who cares?

This is the Semantic Web. This is Linked Data. And it is changing the way people works.

  1. I am professionally working in the Semantic Web field for more than seven years now
  2. according to their RDFa schema
  3. Ontologies Driven Applications is a concept Structured Dynamics introduced a few years ago. Keep in mind that some of the systems referenced in this blog post are not existing anymore, and have been superseded by the Open Semantic Framework (OSF)
  4. this is a completely random number coming out of my intuition

Configuring and Using OSF Entities (Screencast)

This screencast introduces you to one of the most important OSF for Drupal connector: the OSF Entities module. This module creates a new Entity Type called Resource. The description of these entities is managed directly into the Open Semantic Framework (OSF). All the calls to the core entity API function like: entity_load(), entity_save(), entity_create() and entity_delete() are operated with different calls to different OSF web service endpoints.

What this means for a Drupal developer is that they can use Drupal’s Entity API to manage instance records that are hosted remotely in a OSF instance. They don’t have to know how OSF works in order to take advantage of it. They just have to use the API they are used to use. This new Entity Type supports the following Drupal features:

  1. Full Entity API
  2. Entities caching
  3. Revisioning
  4. SearchAPI
  5. Templates selection with inference on their type
  6. 29 field widgets
  7. Export feature in 6 formats

The screencast introduces you to the following aspects of the OSF Entities module:

  1. Introduction to the architecture of the OSF Entities module
  2. Exposing the available entities in OSF into Drupal Bundles and Fields
  3. Browsing and searching for Resource entities
  4. Managing Resource Type bundles
  5. Introduction to the OSF Entity Reference field widget
  6. Creating and updating Resource entities

 


tut_7_blog_400

Registering an OSF Network in OSF for Drupal (Screencast)

In this screencast, I explain how we can link (register) one or multiple OSF Web Services networks to a single OSF for Drupal instance. I discuss how this OSF Web Services mechanism can be used to bring datasets from multiple different OSF instances into the same Drupal portal. I also cover how we can use the same OSF Web Services network as the backend for multiple Drupal portals (which uses OSF for Drupal).

We briefly discuss the distributed aspect of the Open Semantic Framework (OSF), but this topic will be discussed more in deep in a subsequent screencast.

 

tut_5_blog_400

 

The Open Semantic Framework Academy

osf_academy_logo_pillars
The Open Semantic Framework Academy YouTube channel has just been released this morning.

The Open Semantic Framework Academy is a dedicated channel for instructional screencasts on OSF. Via its growing library of videos, the OSF Academy is your one-stop resource for how to deploy, manage and use the Open Semantic Framework. OSF is a complete, turnkey stack of semantic technologies and methods for enterprises of all sizes.

All the aspects and features of the Open Semantic Framework will be covered in this series of screencasts. Dozens of such screencasts will be published in the following month or two. They are a supplement to the OSF Wiki documentation, but they are not mean to be a replacement.

Intro to the Open Semantic Framework (OSF)

This kick-off video to the OSF Academy overviews the Open Semantic Framework platform and describes it in terms of the 5 Ws (welcome, why, what, when, where) and the 1 H (how).

tut_1_blog_400

Installing Core OSF (Open Semantic Framework)

This screencast Introduce you to the Open Semantic Framework. Then it will show you how to install OSF using the OSF Installer script on a Ubuntu server. Finally it will introduce you to the system integration tests using the OSF Tests Suites.

tut_2_blog_400

Open Semantic Framework Web Resources

This screencast will show you all the web sites that exists to help you learning about the Open Semantic Framework. Such websites are the OSF main site, the OSF Wiki, Mike Bergman and Fred Giasson‘s blogs, demo portals such as Citizen DAN, NOW, MyPeg, HealthDirect and Pregnancy Birth and Babies.

tut_3_blog_400

3.5 Million DBpedia Entities in Drupal 7

In the previous article Loading DBpedia into the Open Semantic Framework, we explained how we could load the 3.5 million DBpedia entities into a Open Semantic Framework instance. In this article, we will show how these million of entities can be used in Drupal for searching, browsing, mapping and templating these DBpedia entities.

Installing and Configuring OSF for Drupal

This article doesn’t cover how OSF for Drupal can be installed and configured. If you want to properly install and configure OSF for Drupal, you should install it using the OSF Installer by running this command:

  ./osf-installer --install-osf-drupal

Then you should configure it using the first section of the OSF for Drupal user manual.

Once this is done, the only thing you will have to do is to register the OSF instance that hosts the DBpedia dataset. Then to register the DBpedia data into the Drupal instance. The only thing you will have to do is to make sure that the Drupal’s administator role has access to the DBpedia dataset. It can be done by using the PMT (Permissions Management Tool) by running the following command:

  pmt --create-access --access-dataset="http://dbpedia.org" --access-group="http://YOU-DRUPAL-DOMAIN/role/3/administrator" --access-perm-create="true" --access-perm-read="true" --access-perm-delete="true" --access-perm-update="true" --access-all-ws

Searching Entities using the Search API

All the DBpedia entities are searchable via the SearchAPI. This is possible because of the OSF SearchAPI connector module that interface the SearchAPI with OSF.

Here is an example of such a SearchAPI search query. Each of these result come from the OSF Search endpoint. Each of the result is templated using the generic search result template, or other entity type search templates.

What is interesting is that depending on the type of the entity to display in the results, its display can be different. So instead of having a endless list of results with titles and descriptions, we can have different displays depending on the type of the record, and the information we have about that record.

dbpedia_search_3

In this example, only the generic search template got used to display these results. Here is the generic search results template code:

Manipulating Entities using the Entity API

The Entity API is a powerful Drupal API that let developers and designers loading and manipulating entities that are indexed in the data store (in this case, OSF). The full Entity API is operational on the DBpedia entities because of the OSF Entities connector module.

As you can see in the template above (and in the other templates to follow), we can easily use the Entity API to load DBpedia entities. In these templates examples, what we are doing is to use this API to load the entities referenced by an entity. In this case, we do this to get their labels. Once we loaded the entity, we end-up with an Entity object that we can use like any other Drupal entities:

Mapping Entities using the sWebMap OSF Widget

Because a big number of DBpedia entities does have geolocation data, we wanted to test the sWebMap OSF Widget to be able to search, browse and locate all the geolocalized entities. What we did is to create a new Content Type. Then we created a new template for that content type that implements the sWebMap widget. The simple template we created for this purpose is available here:

Then, once we load a page of that Content Type, we can see the sWebMap widget populated with the geolocalized DBpedia entities. In the example below, we see the top 20 records in that region (USA):

dbpeida_swebmap_2

Then what we do is to filter these entities by type and attribute/values. In the following example, we filtered by RadioStation, and then we are selecting a filter to define the type of radio station we are looking for:

dbpeida_swebmap_3

Finally we add even more filtering options to drill-down the geolocalized information we are looking for.

dbpeida_swebmap_4

We end-up with all the classical radio station that broadcast in the region of Pittsburgh.

dbpeida_swebmap_5

Templating Entities using Drupal’s Templating Engine

Another thing we get out of the box with Drupal and OSF for Drupal, is the possibility to template the entities view pages and the search resultsets. In any case, the selection of the template is done depending on the type of the entity to display.

With OSF for Drupal, we created a template selection mechanism that uses the ontologies’ structure to select the proper templates. For example, if we have a Broadcaster template, then it could be used to template information about a RadioStation or a TelevisionStation, even if these templates are not existing.

Here is an example of a search resultset that displays information about different type of entities:

dbpedia_search_2

The first entity is an organization that has an image. It uses the generic template. The second one is a person which also use the generic template, but it has no image. Both are using the generic template because none of the Organization nor the Person templates have been created. However, the third result uses a different template. The third result is a RadioStation. However, it uses the Broadcaster template since the RadioStation class is a sub-class-of Broadcaster and because the Broadcaster template exists in the Drupal instance.

Here is the code of the Broadcaster search result template:

Now let’s take a look at the template that displays information about a specific Entity type:

dbpedia_entity_view

This minimal records displays some information about this radio station. The code of this template is:

Building Complex Search Queries using the OSF Query Builder

A system administrator can also use the OSF Query Builder to create more complex search queries. In the following query, we are doing a search for the keyword “radio“, we are filtering by type RadioStation, and we are boosting the scoring value of all the results that have the word “life” in their slogan.

dbpeida_querybuilder_1

The top result is a radio station of Moscow that has “Life in Motion!” as its slogan. We can also see the impact of the scoring booster on the score of that result.

Conclusion

As we can see with these two articles, it is relatively easy and fast to import the DBpedia dataset into a OSF instance. By doing so, we end-up with a series of tools to access, manage and publish this information. Then we can leverage the OSF platform to create all kind of web portals or other web services. All the tools are there, out-of-the-box.

This being said, this is not where lies the challenge. The thing is that there is more than 500 classes and 2000 properties that describes all the content present in the DBpedia Ontology. This means that more than 2000 filters may exists for the Search API, the sWebMap widget, etc. This also means that more than 500 Drupal bundles can be created with hundred of fields, etc.

All this need to be properly configured and managed by the Drupal site developer. However, there are mechanisms that have been developed to help them managing this amount of information such as the entity template selection mechanism that uses the ontologies’ structure to select the display templates to use. For example, you could focus on the entity Broadcaster, and create a single template for it. Automatically, this template could be used by sub-classes such as BroadcastNetwork, RadioStation, TelevisionStation and many others.

The Open Semantic Framework is really flexible and powerful as you may have noticed with this series of two articles. However, the challenge and most of the work lies into creating and configuring the portal that will use this information. The work lies into creating the search and entities templates. To properly define and manage the bundles and fields, etc.




This blog is a regularly updated collection of my thoughts, tips, tricks and ideas about my semantic Web researches and related software development.


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