David Huynh completed his PhD at MIT CSAIL last year and joined MetaWeb a few months ago, where he has been working on new and better interfaces to explore the data encoded in their Freebase system. He recently released Parallax as a prototype browsing interface for Freebase. Here is a video that shows the interface in action.
Freebase is “an open database of the world’s information” that is constructed by a Wiki-like collaborative community. In many ways it is like the Semantic Web model, with two big differences: (1) the data is stored centrally rather than distributed across the Web and (2) the representation system is not based on RDF but rather uses a custom built object-oriented data representation language.
Freebase is a great resource. Much of the data is extracted from Wikipedia, so its content has a large overlap with DBpedia. But it is also relatively easy to upload additional information in various structured forms and many have done so, resulting in an extended coverage.
This is clearly a system in the Web of Data space along with the Linking Open Data effort and having it should offer a way for us all to explore the consequences of some of the underlying design decisions.
“2008-06-20: The Semantic Web Deployment Working Group has published a Candidate Recommendation of RDFa in XHTML: Syntax and Processing. Web documents contain significant amounts of structured data, which is largely unavailable to tools and applications. When publishers can express this data more completely, and when tools can read it, a new world of user functionality becomes available, letting users transfer structured data between applications and web sites, and allowing browsing applications to improve the user experience. RDFa is a specification for attributes to be used with languages such as HTML and XHTML to express structured data. See the group’s RDFa implementation report. The Working Group also updated the companion document RDFa Primer. Learn more about the Semantic Web and the HTML Activity.”
Achieving candidate recommendation status is a significant step toward becoming a W3C recommendation. Congratulation to the working group for all of their efforts in developing RDFa.
Joshua Tauberer, a Upenn Linguistics graduate student, maintains rdf:about as a resouce of information on the semantic web language RDF. Its a consise collection of information that manages not to overwhelm and includes good Quick Intro and RDF in Depth pages.
“We invite submissions to the sixth annual Semantic Web Challenge, the premiere event for demonstrating practical progress towards achieving the vision of the Semantic Web. The central idea of the Semantic Web is to extend the current human-readable web by encoding some of the semantics of resources in a machine-processable form. Moving beyond syntax opens the door to more advanced applications and functionality on the Web. Computers will be better able to search, process, integrate and present the content of these resources in a meaningful, intelligent manner.
As the core technological building blocks are now in place, the next challenge is to show off the benefits of semantic technologies by developing integrated, easy to use applications that can provide new levels of Web functionality for end users on the Web or within enterprise settings. Applications submitted should demonstrate clear practical value that goes above and beyond what is possible with conventional web technologies alone.
Unlike in previous years, the Semantic Web Challenge of 2008 will consist of two tracks: the Open Track and the Billion Triples Track. The key difference between the two tracks is that the Billion Triples Track requires the participants to make use of the data set –a billion triples– provided by the organizers. The Open Track has no such restrictions.
As before, the Challenge is open to everyone from academia and industry. The authors of the best applications will be awarded prizes and featured prominently at special sessions during the conference”
“Swoogle has indexed millions of Semantic Web Documents, but how do I know that mine has been indexed?” Here is a simple way – please try your URL using Swoogle Track Back Service. Here I list several example to show how it works:
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About this URL
The latest ping on [2006-01-29] shows its status is [Succeed, changed into SWD].
Its latest cached original snapshot is [2006-01-29 (3373 bytes)]
Its latest cached NTriples snapshot is [2006-01-29 (41 triples)].
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We have found 7 cached versions.
2006-01-29: Original Snapshot (3373 bytes), NTriples Snapshot (41 triples)
2005-08-25: Original Snapshot (3373 bytes), NTriples Snapshot (41 triples)
2005-07-16: Original Snapshot (2439 bytes), NTriples Snapshot (35 triples)
2005-05-20: Original Snapshot (2173 bytes), NTriples Snapshot (30 triples)
2005-04-10: Original Snapshot (1909 bytes), NTriples Snapshot (28 triples)
2005-02-25: Original Snapshot (1869 bytes), NTriples Snapshot (27 triples)
2005-01-24: Original Snapshot, NTriples Snapshot (31 triples)
We may also check the growth of FOAF documents.
http://www.csee.umbc.edu/~dingli1/foaf.rdf
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About this URL
The latest ping on [2006-01-29] shows its status is [Succeed, changed into SWD].
Its latest cached original snapshot is [2006-01-29 (6072 bytes)]
Its latest cached NTriples snapshot is [2006-01-29 (98 triples)].
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We have found 6 cached versions.
2006-01-29: Original Snapshot (6072 bytes), NTriples Snapshot (98 triples)
2005-07-16: Original Snapshot (6072 bytes), NTriples Snapshot (98 triples)
2005-06-19: Original Snapshot (5053 bytes), NTriples Snapshot (80 triples)
2005-04-17: Original Snapshot (3142 bytes), NTriples Snapshot (50 triples)
2005-04-01: Original Snapshot (1761 bytes), NTriples Snapshot (29 triples)
2005-01-24: Original Snapshot, NTriples Snapshot (29 triples)
Finally, this service may also help us learn the life cycle of a semantic web document: it was created, actively maintained, lingered around for a while and finally died (i.e. went offline).
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About this URL
The latest ping on [2006-02-02] shows its status is [Failed, http code is not 200 (or406)].
Its latest cached original snapshot is [2005-03-09 (15809 bytes)]
Its latest cached NTriples snapshot is [2005-03-09 (149 triples)].
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We have found 3 cached versions.
2005-03-09: Original Snapshot (15809 bytes), NTriples Snapshot (149 triples)
2005-02-25: Original Snapshot (12043 bytes), NTriples Snapshot (149 triples)
2005-01-26: Original Snapshot, NTriples Snapshot (145 triples)
NOTICE: Yesterday we posted a form that direct you to Swoogle trackback service. Unfortunately, the form failed when it was called outside our firewall because a Swoogle API key is required. We didn’t notice at first, because we were inside the firewall when we tested it. When we did, we deleted the post, but PlanetRDF had already picked up the post and it was still in our database. Now the form has been removed, but you can definitely go to swoolge web site and try trackback service there.
We’ve set up a Google group, Swooglers, for users of the Swoogle Semantic Web search engine. Anyone can browse the archived and join, but only members can post messages. Replies are sent to the whole group. We’re not exactly sure what Swooglers will have to talk about, but it might be a place to share your experiences in using Swoogle, ask other users for advice, etc.
Recently Cláudio Fernandes asked on several semantic web mailing lists
“Can someone point me to some huge owl/rdf files? I’m writing a owl parser with different tools, and I’d like to benchmark them all with some really really big files.”
I just ran some queries over Swoogle’s collection of 850K RDF documents collected from the web. Here are the 100 largest RDF documents and OWL documents, respectively. Document size was measured in terms of the number of triples. For this query, a document was considered to be an OWL document if it used a namespace that contained the string OWL.
Curently, the version of Swoogle you get by going to http://swoogle.umbc.edu/ is Swoogle 2. Its database has been trapped in amber since last summer, when it was corrupted, preventing us from adding new data. We put our efforts into a reimplementation, Swoogle 3, which will be released early next week. The data reported here is from Swoogle 3′s database.
We noticed a Jose Vidal using a great idea on his publication list which we’ve added to the ebiquity site’s publication page. Jose augments his paper descriptions with data from Google Scholar (GS) — a link to the GS data, the number of citing papers, and a list of their GS data.
We think GS is likely to be increasingly important in the academic/scholarly community. It’s a way to find papers, of course, but also helps judge their significance to the field as measured by the number of citations. Citation counting is the traditional way of measuring the impact of a paper. Using Google Scholar’s citations to measure impact has its problems, a topic we’ve posted on before and is also discussed in the bibliometric circles, but it’s free and convenient, a combination that’s hard to beat. (Writing this, I wonder if anyone has tried a recursive model like that used in pagerank to citation graphs. If not, this would be an interesting experiment to do).
Here’s how our paper listings now works. We augmented the RGB paper ontology to give the paper class a new metadata property, googleKey, that is then used to derive the other properties — the number of citations and links to the GS description and the list of citing papers. Right now getting the GS Key is done manually since automating it reliably is not trivial. But we do have a link on the paper display that makes it easier to find the key by querying GS with the paper title and showing the results. If the paper is in GS, it will probably be on the first page.
Every night, an agent (well, ok, a cron job) checks Google Scholar to update the citation counts for all of the papers that have a GS key.
Our lab members tend to enter papers into the site’s database as soon as they are accepted for publication, which is long before they show up in Google Scholar and even longer before they begin to accrue citations. So authors will have to periodically check recently entered papers and update them with their GS keys when available. It will take some weeks or more before we’ve processed all of the old papers to look up their GS Key. Once we’ve done so, I think it should be easy to maintain it.
SemNews is a prototype application being developed by UMBC Ph.D. student Akshay Java that uses a sophisticated text understanding system to interpret summaries of news stories, publishes the results on the semantic web and provides browsing and query services over them. The project is the result of a collaboration between the UMBC’s Institute for Language and Information Technologies and Ebiquity Laboratory with partial support from the Lockheed Martin Corporation.
SemNews monitors a number of news source RSS feeds and processes new stories as they are published. After extracting a story’s metadata, its news summary is interpreted by the OntoSem text analyzer which does a syntactic, semantic, and pragmatic analysis of the text, resulting in its text meaning representation or TMR. A TMR is a language-neutral description (an interlingua) of the meaning conveyed in a natural language text. In addition to providing information about the lexical-semantic dependencies in the text, the TMR represents stylistic factors, discourse relations, speaker attitudes, and other pragmatic factors present in the discourse structure. In doing so, the TMR captures not only the meaning of individual elements in the text, but also the relations between those elements, and captures both propositional and non-propositional components of textual meaning. OntoSem’s TMRs are represented in a custom frame-based representation language and grounded in the Mikrokosmos ontology, an extensive ontology with over 30K concepts and nearly 400K entities.
Each story’s metadata and TMR are translated into the Semantic Web language OWL via the OntoSem2OWL translator developed for this project. The results are then added to a special collection indexed by the Swoogle search engine and also put into a RDF triple store. These are used to support several services enabling people and agents to semantically browse, query and visualize the stories in the collection, enabling access to information that would otherwise not be easy to find using simple keyword based search.
For example, one can browse through the story collection via the ontology to find stories that involve certain concepts, such as a terrorist organization; find all stories that involve an entities in OntoSem’s onomasticon, such as al qaeda or Karbala; visualize the stories on a map based on the locations they reference; or construct an arbitrary query, such as finding “stories in which the nation named Afghanistan was the location of a bombing event.” Users can also define semantic “alerts” as queries over the RDF triple store and/or the Swoogle collection. For each alert, SemNews will generate an RSS feed of the results.
The SemNews system is currently a research prototype that is being used to refine the underlying technologies and to explore how the sophisticated automatic linguistic processing of text can be integrated into the Semantic Web and conventional web applications. Ongoing work on SemNews includes an evaluation of its semantic recall and precision as well as a service that can group and cluster stories based on their semantic representations.
For more information
Akshay Java, Tim Finin and Sergei Nirenburg, Text understanding agents and the Semantic Web, Proceedings of the 39th Hawaii International Conference on System Sciences, Kauai HI, 4-6 January, 2006.
Sergei Nirenburg and Victor Raskin, Ontological Semantics, September 2004, The MIT Press, Cambridge.
Li Ding, Tim Finin, Anupam Joshi, Yun Peng, Rong Pan and Pavan Reddivari, Search on the Semantic Web, IEEE Computer, October 2005.
AAAI-06 will include a special technical track on Artificial Intelligence and the Web. This year’s conference will Celebrate “Fifty Years of Artificial Intellligence” and be held at the Seaport Hotel and World Trade Center in Boston 16-20 July 2006. The deadline for submitting papers is 16 February 2006.
The track is especially interested in receiving papers in two active research areas: (i) using text and language analysis to interpret and understand natural language text found on the web and (ii) developing and exploiting Semantic Web languages and systems that explicitly encode knowledge using languages such as RDF and OWL. Innovative papers in other areas describing research involving both AI and the Web are also encouraged. See the track web site for details.
The First International Workshop on AAMAS Workshops (WORKSAAMAS?) has been proposed* for the Fifth International Joint Conference on Autonomous Agents and Multiagent Systems.
In summary, I think the software need some more work. Many functions are rough. This doesn’t mean that I don’t like. I think Altova did a great job in being the first commerical company to offer an ontology editor product.
Ebiquity Blog