Alchemy from Raw Text to Semantic Annotations

Alchemy API, a free web API that can be used to semantically annotate web resources such as HTML documents or pure raw texts. The  Alchemy API, uses NLP (Natural Language Processing) to extract the meaning of the input text. Alchemy is capable of retrieving entities, keywords, pure text txtraction, text categorization, language identification and probably some other features that I haven't explored yet. The response of the API is ordinary XML ( RDF included here as well ), which of course, is easy to parse and integrate with any platform. Unlike OpenCalais, which offers typical SOAP web service( which is also a tehcnology I personally admire, you can read my post about it), Orchestr8's Alchemy API uses web requests to their server to invoke their NLP technology. The API is well documented, with downloadable examples for a variety of technologies. Since I am ASP.NET developer, I only downloaded the C#.NET SDK examples and it seems really neat and simple to use. It is very probable that other SDK's are as good as the mentioned one. Please note that you would need  an API key before using this service. This Orchestr8's API, in my opinion bears a lot of potential in dramatically decreasing the effort for semantic annotation of world's web content, which is most likely the stepping stone for the real semantic evolution. An interesting thing that I noticed in the Alchemy's response is that actually contains some kind of entity alignment in it. For instance, it is capable of disambiguation of a given term, so  in the RDF response there is an OWL ontology alignment piece( powered by LinkedData I suppose ), that aligns the disambiguated entity with semantic resources from sources like DBPedia, Freebase, CIA Factbook,GeoNames etc. Really cool. That could boost semantic knowledge management in even more advanced semantic applications.

Orchestr8 offers the API in several packages. The basic package is free and allows 30 000 calls per day, which, is enough for small to medium applications. If a good idea for a semantic web application is born, this certainly will not be the limit.

Triplify: Expose Your Information as RDF

Yet another way into automating the process of semantic annotation of your web content. As many times mentioned, one of the biggest obstacles for the Semantic Web to become fully implemented, is that people (web masters) are forced to manually annotate every resource they have on the Web in order (future) applications to use that information. The trouble is the term future applications. There is no killer semantic web application yet, partly because there is no semantic data available through the Web.

So here comes Triplify into play. Triplify is a framework that works over your SQL database and the web master selects the columns that are of interest when constructing the triples, and it automatically generates RDF using the pattern specified by the owner.

This is an illustration on how Triplify  works:

Disadvantages

Besides the nice approach of generating RDF triples, some serious shortcomings are hidden under the hood. 

First, it has performance issues and is aimed for using on small to medium web sites. 

Secondly, it is still implemented only in PHP. Semantic Web goes far beyond technology limitations. However, more developers are needed for implementations on other platforms.

Conclusion 

 As far I explored, it seems fairly easy to integrate, and it might be very helpful for exporting your data in RDF. But one question still remains.

What to do with RDF ? How does one utilize RDF to make semantic killer application?

What Would You Do With RDF Organized Knowledge ?

So, lets say that there is an ideal tool for creating RDF from your HTML pages. And now what ? This question came to my mind... What is the first application you would write knowing that many sites publish their knowledge in RDF / OWL format ? The sad thing is, I could not answer immediately. So think about it, what would be the amazing benefit of publishing RDF ?
If anyone has implemented such applications, feel free to share them here.

Open Calais: Automatic RDF Annotation of Raw Text

OpenCalais: Automatic Knowledge Extraction

Have you tried OpenCalais? It's a web service that automatically annotates raw text with semantic meaning - it generates an RDF file from it. Well, it's still far from perfect, but it obviously has good performance in semantic annotation of your text. Basically, one can copy & paste the text from her blog and get RDF-structured knowledge based on the text. From OpenCalais say they use NLP(Natural Language Processing) techniques to analyze the text and calculate the relevance of the recognized concepts in the text. It can be very useful for web masters, since this approach can be a true time-saver and one of the easiest steps towards automatic knowledge publication. In my opinion, automating the process of semantic annotation of the web documents from one side and presenting the benefits of the Semantic Web to the web masters are the two crucial steps that need to be taken in order to come closer to the true implementation of the Semantic Web itself. These two steps can end the vicious chicken-and-the-egg circle: Webmasters refuse to put extra effort in embedding knowledge into their web pages, since there are no semantic applications that would use that knowledge and make web masters' life easier. But because there is no semantic knowledge, no real semantic applications can be developed. And this circle goes on and on.

With OpenCalais, you can publish your knowledge via API, so new custom applications can arise from your website, blog, wiki, e-commerce page or similar. I admit I still need to read and play with the Calais to explore its full features, but from what I have seen so far it looks excellent. This article does not aim to advertise OpenCalais in any way, nor I am related to it, but I would like to emphasize the importance of its existence as a service, that could be the stepping stone towards unleashing the power of the Semantic Web.

Moreover, OpenCalais has plugins for Wordpress (ohhh, none of them for Blogger :-( ), to automatically generate tags ( Tagaroo ). OpenCalais also can be integrated with Drupal. Seems like a nice application.

I believe that by using this service, the number of semantically annotated pages will rapidly rise. That will make a good ground for development of even more advanced Semantic Applications. Try the video and go to the site, so tell me what do you think.

Here is how applications can be build on top of it:

You can try the OpenCalais Document Viewer, to see how it generates the RDF output.

It only remains to see if OpenCalais will fulfill its glorious mission. I really recommend OpenCalais to the Semantic Web Community, its effort deserves attention