Florian Huber

Using SPARQL clause VALUES in PoolParty

connect-sparqlSince PoolParty fully supports SPARQL 1.1 functionalities you can use clauses like VALUES. The VALUES clause can be used to provide an unordered solution sequence that is joined with the results of the query evaluation. From my perspective it is a convenience of filtering variables and an increase in readability of queries.

E.g. when you want to know which cocktails you can create with Gin and a highball glass you can go to http://vocabulary.semantic-web.at/PoolParty/sparql/cocktails and fire this query: Continue reading

Andreas Blumauer

Experiences from teaching Linked Data

Dr. Bernhard Haslhofer works as instructor on Web Information Systems at Cornell Information Science. Just recently he gave a course which examined technologies for building data-centric information systems on the World Wide Web. Semantic Web Company (SWC) had the opportunity to talk with Dr. Haslhofer to examine the question “How to teach Linked Data?“.

SWC: Bernhard, you have been working on the Semantic Web and Linked Data for years now. What is the first lesson you usually give when you try to explain the “Semantic Web”?

Maybe I should first clarify that the course I am co-teaching is not a Semantic Web course. The course is about data-centric Web information systems in general and we spent some classes talking about Linked Data and Semantic Web technologies. We start explaining the origins and the fundamental architectural principles of the World Wide Web and then focus on the data-centric aspects of the Web.

“instead of building isolated repository-centric APIs we could also build a globally connected data graph

After introducing various data exchange formats (XML, JSON & co.) we teach how Web APIs work, and discuss the design principles of RESTful Web Services. Then the conceptual transition to Linked Data is just a small step, because we can argue that instead of building isolated repository-centric APIs we could also build a globally connected data graph, which is based on a uniform data model and can be traversed and queried using SPARQL.

“DBpedia and all the other existing Linked Data projects and tools that came up in recent years really help in explaining and illustrating how things work”

So, I am somehow approaching the “Semantic Web” bottom-up and concentrate on the “visible” parts of the “Semantic Web” vision. DBpedia and all the other existing Linked Data projects and tools that came up in recent years really help in explaining and illustrating how things work. And last but not least, schema.org and the design of the Facebook Open Graph protocol also show the growing importance of having structured data on the Web.

SWC: At least for non-technicians “Linked Data” sounds very technical. Antoine de Saint-Exupery said: “If you want to build a ship, don’t drum up people to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea.” Is there an “endless immensity of the sea” you try to bring in as well?

If you can access and combine data from the Web you can answer interesting questions and discover previously unknown relationships between things. We thought the best way to learn about Linked Data is to implement simple demo applications. So we asked the students to think about uses cases that bring some benefit for end users and require data from several Web sources to answer certain questions.

“I think it became clear what it means to work with easily accessible structured Web data opposed to working with unstructured data”

One group developed a service which connects safety records with public transport information. Now users can now easily choose the “safest” bus connection between from and to New York City and other cities. Another group combined public school district information with geographic data, which now allows parents to view statistical information about school districts in New York State by using apps like Google Earth. There are many more examples, but most importantly, I think it became clear what it means to work with easily accessible structured Web data opposed to working with unstructured data.

SWC: Instructing how to use the Semantic Web is not only a matter of slide-decks. It is rather a question of concrete use cases in combination with tool skills. What kind of tool skills should students of information sciences acquire to your opinion?

Collecting and making sense out of data is a common scholarly practice in many research areas and the Web is becoming, or is already, the primary medium for publishing and distributing results. I believe that making data accessible as part of a some research activity will become increasingly important in future and the Web will probably be infrastructure for doing this.

So I think that a student who is working with data should at least know (i) how to retrieve and (ii) how to publish data on the Web in way that others can easily discover, access, and use their data. Linked Data is one possible technical approach for doing that.

SWC: As a European who is teaching and working in the U.S., how do you perceive the different approaches between those two systems when it comes to transfer complex fields of knowledge like the semantic web from universities to business environments?

From the experiences I have made in my previous and current working environments I can only tell that the relations between businesses and universities seem to be tighter in the US. I don’t necessarily mean “formal” bounds between institutions but rather informal relations between people, who understand complex fields of knowledge, both in the academia and in business.

“I assume transferring knowledge between two proxies who speak the same ‘language’ makes it a lot easier”

PhD students, for instance, often work in business over the summer and/or continue their career in the research department of some company. Some continue their cooperation with their former professors and academic colleagues and I assume transferring knowledge between two proxies who speak the same “language” makes it a lot easier.

SWC: What are the most important things which are still missing to make linked data technologies an integral part of enterprise information systems?

Quite often I hear the complaint that major database vendors still don’t provide satisfactory RDF support in their products. I don’t think this is a necessary precondition for implementing Linked Data but for some institutions this seems to be very important.

Many thanks!

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TimBL @ Hofreitschule in Vienna

Right now, 19:30, Tim Berners-Lee is giving a key note on the future of the internet at the Hofreitschule in Vienna, a marvellous, historic venue in the very city.

His talk is a plaidoyer for an open internet, that works independent from central control  and political implications, on top of open standards AND net neutrality. This is especially relevant when it comes to open data, where the social machinery of the web will help to improve many flaws democracy is facing today.

So, what are the implications: Study Web Science! And trigger gentle, non-violent change!

It was a pleasure to listen!



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Tassilo Pellegrini

Interview with Marco Neumann: “It’s definitely an exciting time to be on the Semantic Web!”

Marco Neumann is an Information Scientist and CEO of KONA a consulting and technology service company based in New York City. The Semantic Web activist is an invited expert to the W3C HTML 5 working group. He recently started a discussion on the challenges and difficulties in bringing the Semantic Web into business. SWC asked him for some additional comments.

Marco, you recently initiated a discussion in a Google Group on the difficulty to change Semantic Web standards. What was the background of the discussion? Where do you perceive a need for action?

It’s not so much about changing this existing standards but the challenge to bring them into the world of practitioners and standards developers. The language used in W3C recommendations quite frequently requires advanced topic knowledge and familiarity with the jargon of the discussion about the respective technologies. I recently discussed this with a senior standards maven at the W3C and got the answer that the recommendations can’t be changed retrospectively and that they are intended to be used primarily by vendors for implementation purposes.

Well this might be the case but I also got the impression that Tim Berners-Lee objective for the W3C is primarily to meet the needs of a larger community. And the W3C took this into account for most of the Semantic Web recommendations in the past. Something I still find amazing is the fact that the work process at the W3C is partially and the recommendations are entirely publicly accessible. Though we definitely still need more and better tools to work with semantic web data, higher quality documentation and last but not least more user adoption on the web.

Critics of the Semantic Web often refer to the slow uptake of Semantic Web standards by industry. Is standards adoption actually a valid and sufficient metric to evaluate the maturity of a standard? What would be needed to accelerate the uptake?

I think we might see a similar scenario to the uptake of HTML in the early 90s, a relatively small number of technology mavens will pave the way towards making the Semantic Web more attractive as a technology solution for a wide range of applications and will successfully publish open data before we see business application developers make use of Semantic Web standards.

The availability of trustable and quality approved RDF data is crucial for the success of the Semantic Web. Given the fact that the aggregation business on the WWW is highly concentrated the corresponding formula is simple: If Google just consumes but does not give back RDF the Semantic Web won’t scale. Do you agree?

Yes and no. Yes we need better and more semantic data on the Web, but we will also need better ways to deal with trust in a lightweight and web friendly fashion. I currently see a number of semi automated approaches emerging  that could scale on the web. An example are distributed user based recommendation systems to validate authenticity, open Wikipedia style community evaluation and content curation a la freebase. Increased public accountability for data producers might be an interesting venue as well. In regards to Google I’d say web search engines will go where the web goes. A problem I might see arising is that web search engines will initially develop their own standards to deal with the emerging Semantic Web and confuse users on the web or might pursue a time consuming power play with the W3C. I see a little bit of that in the current discussion in the HTML 5 working group.

As we know from social sciences technological standards are necessary but always incomplete and unsatisfactory. From a standards design and outreach perspective: What would it need to make the Semantic Web flourish?

I’m not sure if we really know all that much about the laws of innovation and the evolution of technology standards at this point. If we draw from the short experience with the World Wide Web I would come to the conclusion that innovation takes place in small to medium size teams that pursue an independent vision of how services should be delivered and how the technology should be designed. In addition Tim Berners-Lee’s encourages the production of lots and lots of data to bootstrap the Semantic Web and create a pull for services in the industry. And indeed we really see some traction for example with the Linked Open Data and Open Government initiatives. It’s definitely an exciting time to be on the Semantic Web!

About Marco Neumann

Marco Neumann is an Information Scientist and CEO of KONA a consulting and technology service company based in New York City. KONA provides semantic technologies to businesses solutions and adds value to products and services in a highly networked economy. In addition Marco currently acts as an Invited Expert to the W3C on the HTML 5 working group and is the director of the global semantic social network lotico.com.