Eric Franzon

During his last ten years with Wilshire Conferences, Eric Franzon has been exploring the world of enterprise data. As VP of Semantic Universe, he has worked to raise awareness and explain the usage of semantic technologies in business and consumer settings. A lifelong learner and teacher, Eric is frequently called on as a consultant, coach, and trainer around complex technical topics. He is an advisory committee representative with the World Wide Web Consortium ( and an Affiliate Analyst with Guidewire Group ( Eric has taught improvisational comedy, early childhood education, blues harmonica, and gender studies. He lives in Los Angeles.

Q & A – Callimachus: Semantic Web Apps Made Easy

Q&A Session for "Callimachus: Semantic Web Apps Made Easy"

Q: Was Callimachus arguing against a "single inheritance" hierarchy or arguing against a universal "Thing" which is the superclass of all things?

A: Callimachus, the Greek poet, could easily justify placing many of his scrolls (of short poems) in multiple bins. He argued that some things have multiple categories (or types) and could not be arranged in single hierarchy.

Q: Can I use html 5 with this?

A: Callimachus serves the constructed pages using an HTML serialization with no doctype and a content type of text/html. Because of the missing doctype and HTML serialization Callimachus cannot serve standard HTML5 documents.

Q: Is Callimachus able to draw on the ontology, for example, to create a pull-down menu based on an enumerated class?

A: Callimachus will read the ontology into the RDF store for querying when placed in the webapps directory. However, Callimachus cannot query rdf:List (used for OWL enumerations) for drop downs. If however, these enumerations have a unique rdf:type relationship, they they can be populated in a drop down.

Q: I am wondering if there is a way for the form which creates a new resource to accept dynamic content from the user instead of having predefined entities in the xml file? Also, where are the new resources stored?

A: Using client side JavaScript, the RDF in the create/copy page can take on many dynamic forms. However, only triples that are about the target resource and match a basic graph pattern in the RDFa template can be created using the copy operation. New resources are stored in the embedded RDF store by default.

Q: Is it possible to have essentially a wild card for Delete you don't have to specify all the properties?

A: Not in the current version of Callimachus, but this may change in subsequent versions.

Q: Any thoughts of an IDS sort of interface for creating Callimachus templates rather than crafting raw XML? (such as pick a property from a dropdown and enter the specific parameter)

A: There is no UI builder in the current version of Callimachus, although such a feature is desirable in future versions.

Q: So, my understanding is that each of the templates has to be hand-written, is this correct?

A: The templates must either by hand written or generated from an XSLT. You can, for example, use XSLT to generate RDFa templates from a particular RDF/XML encoded ontology.

Q: Is it possible to share code between the templates? for example to have a footer or header on every page?

A: Callimachus provides a common header, footer, and navigation menu for templates that use the XSL stylesheet "/layout/template.xsl". This is a fairly simple XSLT file that can be found in the layout.war file. RDFa templates are free to use alternate XSLT files to include common sections. The XSLT is applied to the RDFa template before the RDFa is parsed.

Q: I thought a strength of RDF was to be able to add schema and data at runtime. Does the templating in Callimachus force the schema to become static? (i.e. if schema changes, Callimachus can't take advantage of it)

A: The schema is defined in the HTML. By changing the HTML Callimachus will start to use the new version right away.

Q: How complex can the RDFa schemas get and still be useable by the simple(?) query language that operates over them?

A: The RDFa template syntax is not as expressive as SPARQL. There is no way to express the type of join, there are no filters, or limit. For complex queries, SPARQL is still better. Callimachus can serve named sparql queries that are defined in a Turtle file within the webapps directory. Open the layout.war and take a look at the menu.ttl for a simple example and lookup.ttl for an example using SPARQL+XSLT.

Q: What size RDF files can Callimachus handle?

A: On startup Callimachus will crawl the webapps directory and upload any .rdf and .ttl files into the RDF store. Too many or too large .rdf and .ttl files can slow this down. Instead, bulk RDF can be loaded into Callimachus using an authenticated PUT request. See the page on RDF Import for details.

Q: What exactly are the .war files?

A: The .war files are a compressed (zipped) directory with the .zip extension renamed to .war. These files should not be confused with J2EE webapps.

Q: Is Callimachus a runtime environment, a development environment, or both?

A: Callimachus watches the webapps directory and "uploads" any changes to an internal data store. Callimachus will queue and lock the data store to allow uninterrupted service while changes are being made to the webapps directory. Watch the log files for parse errors that occur during the upload.

Q: Can we use this with Java?

A: Callimachus uses OpenRDF AliBaba for RDF-object mapping and object server. These libraries provide an interface for triggers written in Java and ways to intercept HTTP requests. Post any further questions on this to the discussion group.

Q: Can Callimachus be used to create applications outside of the Callimachus container (i.e. Spring Framework)? If not out of the box, does it have an API which can be used to accomplish this?

A: Callimachus does not publish an API for external use, although that could change in the future.

Q: How big can the repository be?

A: This of course depends on the hardware. Using commodity hardware with default configuration things may slow down at 100 million triples.

Q: Where is the repository being queried specified?

A: Callimachus uses an embedded RDF store by default that is specified in the Java resource META-INF/templates/callimachus-config.ttl.

Q: Is there any inference engine available, other than what is available through SPARQL?

A: Callimachus uses the Sesame API and can use any inference engine or store available through a Sesame interface.

Q: What is the SPARQL edit /submission tool you're using?

A: The browser plugin used in the demo is available in Firefox and Chrome as "HTTP Response Browser".

Callimachus: Semantic Web Apps Made Easy

Date: September 15, 2010, 11:00AM (1 hour)
Register: View the recorded webcast
Q&A: Q & A – Callimachus: Semantic Web Apps Made Easy


RDFa makes it easy for Web publishers to expose data on the Web, but RDFa can also make it easy to develop Web data applications. Watch how easy it is to replace complex data schemas and their SQL queries with simple RDFa attributes in your HTML markup!

In this webcast, James Leigh, a lead developer (with David Wood) on the Callimachus Project, will show us how a Web developer can create semantically-enabled Web applications with a minimal knowledge of the internals of the Semantic Web and SQL. For further details, see Callimachus Project at


  1. This webcast walks you through some of the sample applications with Callimachus. To find out more about these sample applications and to download them, visit:
  2. Callimachus uses the Turtle syntax for its configuration files. The Turtle syntax is explained here:
  3. RDFa is used in the template language of Callimachus. An introduction to RDFa (the data format) can be found here:
  4. During this webcast some browser extensions are used, they can be downloaded here:


James Leigh
James Leigh
Independent Software Consultant
James Leigh is an independent Software Consultant based in Toronto. James is a co-creator of Callimachus and is involved in other public semantic Web projects, such as the PURL server and Sesame store. James has been building web applications for ten years with emphasis on performance and technology integration. His experience modelling business problems and concepts in software has enabled his clients to rapidly move from concepts to prototypes to production systems.

Strengthening the Four Pillars of the Advanced Enterprise through Semantics; Data, Processes, Resources, and Access

Date: May 13, 2010, 11:00AM (1 hour)
Register: View the Recorded Webcast
Attachment: fourpillars.pdf (13.59 MB)

Data management, process management, access management, and resource management form the four pillars of the advanced computing enterprise. This includes critical technologies such as databases, web services & service oriented architectures (SOA), mobile devices, and cloud computing. Semantics helps adapt and unify them to your current enterprise to allow rapid adoption and effective use.

We outline and demonstrate the potential contributions of Semantics to each of the four pillars. The contributions exist along two dimensions; making each pillar operate more effectively and making semantics work more effectively through effective implementation of the pillar. This provides you with choices as to how focus your needs with potential semantic contributions.

We end by establishing an incremental, iterative plan outlining risks and benefits to allow you to gracefully incorporate Semantics into these critical enterprise areas.

  • Host semantic solutions in advanced enterprise technologies
  • Enrich key enterprise technologies with semantic extensions and enhancements to improve efficiency, effectiveness, functionality, and quality.
  • Identify semantic opportunities in the enterprise.
  • Outline a pragmatic plan for semantic enrichment


Matt Fisher
Matt Fisher
Progeny Systems

Matt Fisher is a Principal Systems Engineer at Progeny Systems who enjoys discussing the Semantic Web to the point that his wife hopes he gets a new hobby. 

John Hebeler
John Hebeler

Q&A Session for “The RDFa initiative in Drupal 7, and how it will impact the Semantic Web”

Q: How are the colleagues generated in the example? Manually nominated or picked up automatically by some social networking function?

A: The example you are referring to is a typical website built with Drupal and Fields (formally known as CCK) where the users have created pages (of type person in the example) and they filled in all the information like name, picture and also they choose the list of colleagues from the list of other person described on the site. The colleagues haven’t been picked from a social network. This example only illustrating the generation of social network data with Drupal and its export in RDF. The other way around (importing) is something more tricky which is still at a prototype stage and should be available in the future for Drupal.

Q: How do we use of facebook as a source in Drupal?

A: Yes, you can use Open Graph protocol module for Drupal 7 I created a few days ago.

Q: Will you be persisting RDF data and if so by what mechanism?

A: Drupal core does not store RDF data as triples, but instead it generates the RDFa markup on the fly. Because the RDF mappings are defined ahead of time and not really RDFa specific, the data contained in a Drupal site can also be expressed in RDF triples and stored in an RDF store. In fact the RDF module which you can download for Drupal 7 already allows to get RDF/XML for each page of the site. There will be shortly a module to federate all this RDF data into a local store and expose it via a SPARQL endpoint.

Q: Please advise the whitepaper and example references you mentioned.

A: All the relevant links have been added to the webinar announcement.

Q: How big does the vocabulary in RDF & RDFa need to be before the general user population finds it useful?

A: I’m not sure to understand the question 100% but I’ll assume you’re talking about the amount of RDF triples on a given page. A few triples can make quite a difference for machines to understand what information they are looking at. To take a more practical example, you only need to have four elements in RDFa to have your page reusable by Facebook. Similarly, Yahoo! and Google only require a few triples to start making your data available as enriched search results. Typically less than 10 triples are enough to get a decent looking search result.

Q: So if we are not quite ready to try Drupal 7 in alpha, what do we need to install on Drupal 6 to play with RDFa?

A: I would recommend to wait until you can move to Drupal 7. RDF in support in Drupal 6 is quite difficult to set up, and there are feature like RDFa which are not really supported. Drupal 7 core has been design so that it’s possible to output RDFa and works better with RDF in general. Aside from that, Drupal 7 also has a lot of new features in term of usability, testing, APIs.

Q: Do you have any query interface built for querying RDF data?

A: That more of a generic RDF question which not only applies to Drupal but any application producing RDF data. See Freebase’s Parallax and Sparallax developed by DERI.

Q: Can you speak more about mapping and make some recommendations?

A: Drupal 7 core ships with some default RDF mappings for each built in content type like blog posts, articles, forums. You can change them or specify mappings for the new content types you might create on your site with the RDF module.

Q: Are there important RDFa standards to follow when setting up content types and fields so that they are represented consistently by search engines, etc?

A: Yahoo! and Google are still aligning their vocabularies. The best place to get the latest specifications is their webmaster documentations: Yahoo! SearchMonkey: Getting Started and Google Rich Snippets.

Q: When will a browser be able to follow RDF links?

A: Regular browsers like Firefox are already able to browse HTML pages which contain RDFa, except they are not yet able to understand what type of links they are traversing. For an RDF specific browser, see Tabulator.

Q: Also, what happens if/when there are changes made to RDF information types – how do they propagate and "push" the notification of changes to the sites displaying the data?

A: The syndication mechanism can be either a pulling of the information every so often like it is the case with regular RSS. A more sophisticated method can involve a pubsubhubbub setup where subscribers are notified every time there is a change. The work for integrating RDF and pubsubhubbub is currently on-going, see an example with sparqlPuSH

Q: Thanks for inviting me in this great seminar. I have an ontology which was implemented in OWL. May I import it into Drupal? What kind of modules I need to import using the specific ontology in Drupal, instead of generating RDF inside the Drupal?

A: The RDF mapping API in Drupal has been designed so it can deal with any ontology. The RDF external vocabulary importer in Drupal 6 was the first prototype of a module allowing to import any ontology into Drupal. It is currently being ported to Drupal 7 and you will be able to import your custom ontology to map your Drupal site data structure to your ontology.

Q: How ready is Drupal 7? I am an experienced developer but no Drupal experience

A: Drupal 7 is definitely usable: you can install it, create your site structure and create pages. It is not recommended to go production with it yet since there are still some known issue, but a good strategy is to start getting used to its new user interface and many other improvements; and start planning how you want to build your site with Drupal. Drupal 7 will be stable when all bugs are fixed, so if you are a developer you can help fix these remaining bugs. If you are not a developer there are many other ways you can contribute. New users are encouraged to download Drupal 7 and try it out.

Q: In your example you have the term ‘bear’ defined as a SKOS concept. I didn’t see any namespace in the markup. Would there be one or are all bears equal?

A: The namespaces in Drupal 7 are located at the very top of the HTML document, in the html tag. Drupal 7 includes the namespaces of Dublin Core, FOAF, SIOC, SKOS, etc. Developers can add their own custom namespaces via the RDF mapping API.

Q: Will Drupal 7 support discovery of vocabularies, and, help the administrator to choose the most appropriate vocabularity?

A: Yes, it will. The Produce and Consume Linked Data with Drupal! paper (PDF) goes well in details of the approach we are planning to use in Drupal 7.

Q: How easy will it be to tag a persons name in an article?

A: Drupal core does not deal with unstructured data within, say, the body of an article. People interested in this should look at modules like Calais or Zemanta which will detect these entities automatically for you.

The RDFa initiative in Drupal 7, and how it will impact the Semantic Web

Date: April 30, 2010, 11:00AM (1 hour)
Register: View the Recorded Webcast
Q&A: Q&A Session for “The RDFa initiative in Drupal 7, and how it will impact the Semantic Web”
Attachment: RDFa-in-Drupal-7-Slides.pdf (2.15 MB)

Drupal 7 (alpha), the latest major release of the popular open source CMS, includes a lot of features for web publishers interested in implementing Semantic Web Technologies.

In May of 2009, Google announced the support for RDFa as part of its Rich Snippet program. At the time, the work for integrating Semantic Web technologies into the next release of Drupal’s core had already started. In May, 2010 at DrupalCon San Francisco, Dries Buytaert – creator and project lead of Drupal – reaffirmed the community’s strong support for RDF in Drupal 7 by showing what sort of applications this will enable. A few days later, Facebook announced the Open Graph protocol, a new protocol based on RDFa which allows for turning any webpage into a rich object in a social graph. Clearly, the future is in the Semantic Web. This webinar presents some brief history about semantics in Drupal and the various facets of RDF and RDFa which are available today as part of Drupal 7 alpha.

At the SemTech 2010 Conference in June, Stéphane Corlosquet, Lin Clark, Alex Passant and Axel Polleres will present a hands-on Tutorial on "How to build Linked Data sites with Drupal 7 and RDFa."

Relevant links mentioned during the webinar:


Stephane Corlosquet
Stephane Corlosquet
MGH / Partners

Stéphane Corlosquet has been the main driving force in incorporating Semantic Web capabilities into the Drupal CMS. His ‘RDF CCK’ and ‘evoc’ contributed modules to Drupal 6 have naturally evolved to be accepted as standard within the core of the upcoming Drupal 7. He co-authored the ISWC 2009 Best Semantic Web In Use Paper titled "Produce and Consume Linked Data with Drupal!". Stéphane recently finished an M.Sc. in Semantic Web at the Digital Enterprise Research Institute (DERI), Ireland and joined MassGeneral Institute for Neurodegenerative Disease (MIND), MGH as a Software Engineer to work on the Science Collaboration Framework, a Drupal-based distribution to build online communities of researchers in biomedicine. For more information, see

Q&A Session for “Introduction to Linked Data” webcast

Q: Can you go back to more clearly describe RDF?

A: You might have a look at this short introduction to RDF (note the date!) written by my business partner, Uche Ogbuji:

A longer and more complete introduction is available here:

Q: Are Apple apps already using SPARQL and LOD at consumer level, or are they using different method?

A: Apple apps use many of the W3C standards, but as far as I know they are not using SPARQL or LOD techniques. The big announcements around RDF usage by major consumer-oriented companies in the past year have been Google and Yahoo’s support for parsing RDFa from Web pages and Best Buy’s use of RDFa to increase their page ranking on those search engines.

Q: How does SPARQL fit with RDF?

A: SPARQL is a query language for distributed RDF data in the same way that SQL is a query language for relational databases.

If you want to see how to create SPARQL queries for real, try these:

Q: Can you also elaborate more on how LOD can overcome scalability issues?

A: Linked Data approaches consist of standards, formats, tools and techniques to query, resolve and analyze distributed data on the World Wide Web. Linked Data is based completely on the standards of the Web. The Web is the largest and most complex information system ever fielded because of scalability principles built into those standards. Roy Fielding, in his doctoral dissertation, captured and analyzed the properties that make the Web scalable. He called the collection of those properties Representational State Transfer (REST). Linked Data is built on REST. Roy’s dissertation is quite readable for a thesis and may be found at:
Fielding, R.T. (2000). Architectural Styles and the Design of Network-based Software Architectures. Doctoral dissertation, University of California, Irvine.

Q: When do you have to use absolute URI’s in RDF?

A: There are several different ways to store RDF information. There are at least five commonly-used document formats (RDF/XML, OWL/XML, Turtle, N3, RDFa or raw triples – I prefer Turtle), the SPARQL Query Results XML Format and the SPARQL query language itself. Most RDF systems exchange information using one or more of those formats. The syntax of the particular format dictates whether URIs must be absolute or whether they may be simplified. Most (e.g. RDF/XML, OWL/XML, RDFa, Turtle, N3, SPARQL result set and query language) allow some mechanism to shorten URIs (variously called "namespaces" or "compact URIs").

Q: Data inflation – great slide!

A: Thanks!

Q: What is your understanding of the relationsip between the semantic web and the human mind (e.g., what practices promote learning, development of expert-like knolwedge architecture, and generative thinking?)

A: There may be a good reason to use an associative model to describe information: Human memories have been claimed to be associative in nature [Collins 1975], and recent functional magnetic resonance imaging studies lends credence to that view [Mitchell 2008]. See the following for details if you don’t already know them:

Collins, A.M. and Loftus, E.F. (1975, November). A Spreading-Activation Theory of Semantic Processing. Psychological Review, 82, pp. 407-428.

Mitchell, T.M., Shinkareva, S.V., Carlson, A., Chang,K.-M., Malave, V.L., Mason, R.A. and Just, M.A. (2008, May 30). Predicting Human Brain Activity Associated with the Meanings of Nouns, Science, 320 (5880), pp. 1191-1195.

Q: I’m intrigued by the enabling of discovery; can you point to an application demonstrating it in a LOD project?

A: Sure. Try these:

For the more technically minded, see the W3C’s expose on The Self-Describing Web:

Q: Seems like most of the project on Linked Data are academic/non profit projects. Why are there not more commercial projects on Linked Data?

A: There are many commercial projects using Linked Data, they just tend to be more circumspect. Some notable exceptions are Google and Yahoo’s support for parsing RDFa from Web pages and Best Buy’s use of RDFa to increase their page ranking on those search engines. The New York Times was a welcome addition. The BBC both provides data and uses it internally. The forthcoming book I mentioned from Springer (Linking Enterprise Data) will have more.

It is worth noting that the Linked Open Data (with a focus on "open") does not appeal to most businesses. That doesn’t mean that many businesses aren’t exploring or actively using Linked Data techniques.

Q: Just a comment– How we understand these relationsips inside our heads is referred to as structural knowledge. This is also the underlying idea behind concept maps.

A: Right. The same psychological research is behind RDF.

Q: What new security concerns do you see appearing as the web suppports more semantic data/queries?

A: There are several significant challenges for information security. Some of them are:

  • Changing DNS domain holders. If you query some RDF at a given DNS domain for a long period of time, how do know whether the DNS domain changes hands? You might one day be querying a different resource controlled by someone else.
  • International Resource Identifiers (IRIs). Intended as the internationalized replacement for URIs (so, e.g., Chinese people could have Web addresses in Chinese), IRIs are a boon to black hats (which has slowed their adoption). Consider clicking a link that reads, but might go elsewhere because the character set of the address *looks* like US ASCII, but is really in another alphabet.
  • URI curation. Systems like PURLs (see allow management of the URI resolution process. This can be a benefit for security, or a detriment, depending on who does the curation.
  • Lack of technical trust mechanisms. We solve almost every issue of trust on the Web today socially. If Linked Data clients follow links (semi)automatically, how will they know when they are beyond trust boundaries?

Q: recommendations for best way to start?

A: I recently surveyed a good number of big companies who successfully fielded Linked Data solutions into production (I notice you are from a big company). Successful organizations had at least three things in common:

  • They all had at least one Semantic Web expert on staff.
  • They all worked on at least one real business problem (not a prototype or proof-of-concept).
  • They all leveraged existing investments, especially those with implied semantics (such as wikis or email).

Q: Are there performance optimizations available when working with RDF data? Can a PB of RDF data be queried in real time?

A: Absolutely yes. Querying an RDF database is going to be much faster than querying a bunch of RDF documents in XML format. Some Open Source RDF databases to look at include:

If you want to pay, try these:

Q: The mixing to which you just referred seems to imply "trusted" sources. Could you discuss?

A: Sure. Just like with anything on the Web, the best kind of trust is socially-developed trust. We think we can trust Google to deliver objective search results. We think we can trust Amazon to give us real used-book prices. Similarly, we think we can trust major stores, publishers and governments to describe their own data well. We may be less sure of sites we don’t know. Some of the sites on the Linked Open Data cloud are very trustworthy (such as the scientific ones or the New York Times) and others less, perhaps due to their underlying data sets (such as DBPedia’s scrapping of Wikipedia). You can trust Wikipedia for some things (such as "hard" information like the periodic table or the location of Massawa) but not so much in regards to contentious subjects like climate change or political figures.

When you write SPARQL queries, you have to name your data sources. You therefore get to choose who you trust and for what.

Q: Anything on how to reuse vocabularies? The alphabet soup makes finding the right schema or OWL ontology just as bad as finding a webpage was in the early days of the web…

A: Yes, it does. There have been several attempts to make sense of the soup by allowing people to look up terms and vocabularies, but none have become dominant yet. A summary of the state of play (a bit dated) is at:

Some ones to look at are:

Q: If we use the web as a database, are there any tools that map the schema, attributes, and attribute properties of the linked data?

A: Good question! Schemas on the Semantic Web are composed of the predicates (the URI-addressable terms linking two things) and additional information describing those predicates. When one creates a SPARQL query, one explicitly lists the Web addresses to data sources to query (because you couldn’t practically query the entire WebÉ). Putting those two statements together, it is possible to query your identified data sources for just the predicates they contain, and then the information about those predicates. That would give you the schema, attributes and attribute properties for those data sources. So, the tool you need is simply a SPARQL endpoint that will accept the SPARQL query you need to write.

Q: Relate at what level of granulairty? Page to page or idea unit to idea unit?

A: Both. Neither. It depends :) I suggested during the webinar that one not try to solve all problems from a top-down perspective. Instead, publishing just the data (and just the relationships) that one needs to solve a particular problem seems to work best, especially in larger teams of people (building top-down consensus can take a long time!).

In your particular case with Hylighter (if that was your question), you might consider objects like people, comments, documents and times so you could perform queries like "show me comments made by Peter on document x between 2:00 and 4:00". Capturing subjects or topics would be harder in your free-form environment, but some people use server-side entity extractors to try things like that. They sometimes work.

Q: Would you recommend a specific RDF, etc. authoring tool (WYSIWYG or otherwise) or is a good old text editor (along with heavy dose of "copy and paste" from existing RDF docs) still the best way to go?

A: I used to joke that programmers in my company could use any IDE they chose: vi or emacs. Text editors work just fine. You may have heard Eric Franzon say that he used Dreamweaver to add RDFa to the Web site he developed. I’ve seen demos of TopQuadrant’s TopBraid Composer (, which seems nice if you like a graphical environment. For ontology development, some people prefer Protege (, but I like SWOOP ( for its better debugging capabilities. The Eclipse IDE and the Oxygen XML editor also have some support. It really depends which of the many possible jobs you are trying to accomplish and the kind of environment you feel most comfortable in.

NOTE from Eric Franzon: Yes, I did use DreamWeaver, a text editor, and some heavy use of Copy/Paste.

Q: reusing terms/names is all very well but it’s important to understand the MEANING e.g. is one ‘customer’term the same as another?

A: Absolutely! Choosing terms to use on the Semantic Web is equivalent to choosing terms in any other information processing system. You do need to be careful to say what you mean. Fortunately, RDF terms are resolvable on the Web itself (by following terms’ URIs). Each RDF term should provide the ability for a user to read exactly what the author of the term meant it to mean. That situation is better than the short and ambiguous meanings of terms generally associated with IT systems (such as relational database schemas or spreadsheet column names).

Q: Are there query clients for the semantic web?

A: Sure, although at this point most programmers are making their own. There is no de facto standard tool in use by a dominant number of people. You might have a look at these for enterprise use:

If you just want to try a few queries for yourself, try these:

To get some data to play with, try here:

Q&A Session for The National Information Exchange Model and Semantic-Driven Development

Q&A Session for "The National Information Exchange Model and Semantic-Driven Development"

Following the webcast, Dan McCreary answered questions from the live audience. Here is a transcript of that discussion.

Q: My understanding is that NIEM is not considered a Federal Information Exchange Model and does incorporate Federal, State, Local, Tribal and Private Sector partners.

A:[Dan McCreary] I am not sure of the meaning of the question. NIEM is a US federal standard and is being used by federal, state, local, tribal and private sector partners. Perhaps the word "not" was a typo? Please see the NIEM web site for more details.

Q: Does NIEM and/or contain vocabularies expressed in RDF/OWL?

A: Not exactly, but you can easily convert the NIEM Core and other XML Schema files into an OWL file. The code is only about 20 lines of XQuery. Please send me an e-mail at if you would like a me to send you a copy of the source. I have published it using an Open Source Apache 2.0 license.

Q: When would one use SKOS in place the ISO/IEX Metadata repository standard?

A: SKOS is typically used at the beginning stages of the creation of a metadata registry. You start by capturing preferred business terms and their definitions using a simple SKOS editing tool (also available as an open source XRX application for eXist). Next you can start to group related terms using the "broader" tag. After that you can start to link terms together in a taxonomy and classify terms into subsets using "SKOS Schemas" for ISO classifiers. You can then start to see your full ontology forming from the business terms that are grouped together. From there you can mark each SKOS "concept" as being a potential "Conceptual Data Element" and migrate it into your ISO/IEC registry. From there you can create OWL reports.

Q: Sorry, that meant to ask, when would one use SKOS in place of the ISO/IEC Metadata Repository standard?

A: See above

Q: What is a uri?

A: A universal resource identifier. It is like a URL but it might only point to a "concept", but not necessarily a real web page. It is really a way of creating a site-specific way of identifying resources so that they can be merged with other resources on the internet.

Q: What is your view regarding acceptance of alias’es for element names?

A: Aliases are VERY important for aiding search, but should always be marked as such. Aliases are important for fundability of a the "official" or "preferred" term. But tools should prevent people from ever putting aliases in wantlists or subschemas. This would make it harder to merge graphs from different systems.

Introduction to Linked Data

Date: April 21, 2010, 11:00AM (1 hour)
Register: View the archived webcast
Q&A: Q&A Session for “Introduction to Linked Data” webcast
Attachment: LED-slides.pdf (1.06 MB)

Linked Data (or Linked Open Data) is an emerging set of concepts and technologies for combining and integrating data. Originating on the World Wide Web, the simplicity and scalability of Linked Data is now bringing the concept into enterprise data architectures as well. As enterprise data is growing at a much faster rate than traditional technologies can cope, some different approach to large-scale information management is warranted. The World Wide Web is the only information system we know that scales to the degree that it does and is robust to both changes and failure of components.

At the 2010 SemTech Conference in June, David Wood will present a half-day tutorial on Linked Enterprise Data with his colleague Bernadette Hyland.

NOTE: The slides for this session are available to registered members of Semantic Universe only.
Please sign in to the site, and a link to download the slides will appear. If you are not a member, please consider joining today. Membership is free.


David Wood
David Wood

David Wood is a partner with Zepheira and software engineer/entrepreneur specializing in disruptive technologies. He is a co-founder of the Kowari, Mulgara and PURLZ Open Source Software projects. Dr. Wood has been involved with Semantic Web research and standards efforts since 1999.

The National Information Exchange Model and Semantic-Driven Development

Date: April 14, 2010, 11:00AM (1 hour)
Register: View the archived webcast
Q&A: Q&A Session for The National Information Exchange Model and Semantic-Driven Development
Attachment: NIEM-Slides-v2.pdf (2.36 MB)

Since 2002, several US federal agencies have been deploying XML standards for the exchange of complex data sets. Led by a large project at the US Department of Justice and homeland security, there are now hundreds of states and vendors supporting an emerging XML standard called the National Information Exchange Model or NIEM. This presentation will look at the NIEM processes and show how they are being used to promote semantically precise data exchanges as well as promoting transparency in government. We will compare ISO-based NIEM processes with RDF and OWL and show how they complement each other.

The slides for this session are available to registered members of Semantic Universe only. Please sign in to the site, and a link to download the slides will appear. If you are not a member, please consider joining today. Membership is free.


Dan McCreary
Dan McCreary

Dan is an enterprise data architect/strategist living in Minneapolis. He has worked for organizations such as Bell Labs and Steve Job’s NeXT Computer as well as founding his own consulting firm of over 75 people. He has a background in object-oriented programming and declarative XML languages (XSLT, XML Schema design, XForms, XQuery, RDF, and OWL). He has published articles on various technology topics including the Semantic Web, metadata registries, enterprise integration strategies, XForms, and XQuery. He is author of the XForms Tutorial and Cookbook.

Semantic Search Beyond RDF – SemTech 2009 Video

Wen Ruan, TextWise

Ronald M. Kaplan, Powerset division of bing
Christian F. Hempelmann, RiverGlass, Inc.
Riza Berkan, hakia

Semantic Search technology in the Semantic Web community is often understood as retrieval of knowledge from tagged data such as RDF sources, which require substantial formatting and markup to realize. Understanding unstructured query and document text and conducting searches according to their meaning is another approach, exemplified by linguistically rooted semantic matching, ontological knowledge-based semantic interpretation, and statistically based semantic similarity search.

This panel will look at different ways to tackle semantic search as a problem of text understanding. Powerset division of bing’s natural-language processing engine does deep syntactical analysis to determine the meaning of a query or a sentence. Hakia relies on a language-independent ontology model and an ontology-based English lexicon to translate text into a representation of its meaning. RiverGlass has developed an ontological semantic approach to search and text analytics, emphasizing the in-context, linguistic meaning of textual content in order to return truly relevant results in response to information requests. TextWise’s Semantic Signature matching looks for similarities between a query and text at the topic level.

Semantic Search Beyond RDF from Semantic Universe on Vimeo.