Seth Ladd's Blog

Proper web architecture dictates that a you should " Assign distinct URIs to distinct resources ." And Cool URIs for the Semantic Web states that: There should be no confusion between identifiers for Web documents and identifiers for other resources. URIs are meant to identify only one of them, so one URI can't stand for both a Web document and a real-world object. So we know that a URI should refer to one and only one resource. (Of course, you may have many URIs all referring to the same resource.) So why do so many web sites have URIs like http://www.example.org/myaccount ? That same URI is used to refer to any account in the system, depending on who is logged in. And that makes Baby Semantic Web cry. Why is the baby sobbing? A generic URI like http://www.example.com/myaccount isn't useful on the semantic web, because it's very difficult to make meaningful statements about that URI. Let's go and try. http://www.example.com/myaccount is the account ...

The Semantic Web in Action , originally published in the December 2007 issue of Scientific American , is now online and free. The original article published in the May 2001 issue of Scientific American was certainly due for an update. The original article made a lot of grand promises, while the December 2007 article details current efforts at applying semantic web technologies to real life problems. Check it out if you're interested in how companies are building the semantic web today .

Tim Berners-Lee asks "So do you think Flickr could be persuaded to source FOAF ?" Given what I've heard from Stewart Butterfield (co-founder of Flickr), the answer is a No. Back in 2004 (Mon, Nov 29, 2004 at 8:41 PM to be exact), I wrote Flickr asking if they could add sha1 hashes of user emails (in an obvious attempt to be able to convert the data into FOAF). Here's the original request email: Hello, Would it be possible to add a sha1 hash of a person's email address to the response of flickr.people.getInfo ? I understand that we don't want to give out email addresses, and it's nice that the API doesn't expose them. But to help in uniquely identifying users across systems, a good identifier is often their email address. To safe guard against spam, creating a SHA1 hash is a good way to hide the email, yet still provide a unique identifier for the user. This sha1'ed email address becomes a candidate key to the user, so to speak. Thoughts? Th...

When was the last time you had an unambiguous discussion? In which Roy Fielding asks why the Semantic Web has a requirement that URIs identify a resource unambiguously? I believe the whole attempt to make a distinction between a "document" and a "non-information resource" is just way too complicated for most users. All this business of redirecting the client from the non-information resource to a document that describes the resource seems like a hack. I understand the problem (does the URI refer to the Thing or the Document About The Thing?) and it's complicated. Take the link I used to point you, the loyal reader, to more information about Roy Fielding. I used http://www.ics.uci.edu/~fielding/ which is some home page for Roy. Is that link pointing to The Man or The Home Page? My answer? Both. And the semantic web needs to deal with that unambiguity. As far as I can tell, it can. Since anyone can publish metadata about anything on the web, there's ...

Hopefully with Google's OpenSocial API launching Thursday , I'll finally be able to tell Flickr, "Just let anyone that is my friend on Facebook, or in my GMail address book, to view my photos." I'm tired of telling people, "Sure, you can view my photos. Just create an account at Yahoo, then login to Flickr, then let me know your username." I already know these people somehow, and that relationship is somewhere on the web (probably in my address book) so why can't I tell Flickr to use that? The idea of a portable set of relationships which enable cross site permissions is really, really important to the scalability of the web. Our data is spread out, it's in a web. Let's use it on the web!

Radar Networks has come out of stealth to announce Twine , their "revolutionary new way to share, organize, and find information." I've been waiting for these guys to release their application for a long time. Of course I just signed up to be a beta tester.

I should be able to tell Flickr to allow viewing of my photos to any of my Facebook friends.

After reading Semantic Web: Difficulties with the Classic Approach , I am even more certain that we're putting too many expectations on the semantic web. The semantic web doesn't have to be difficult to build or use. It simply starts with resetting expectations and re-branding. To start, the semantic web needs to be re-branded as the Data Web. Now take a deep breath. Doesn't the air feel lighter and taste sweeter? That's because the heaviness of the baggage brought along by the word "semantic" is gone. People see semantic and go all screwy: "Replace humans with computers?" or "How do you deal with uncertainty?" or "How do we agree on what we mean by agreement?" or "A.I. never worked." Even Tim B.L. thinks that the name "semantic web" isn't very good : I don't think it's a very good name but we're stuck with it now. The word semantics is used by different groups to mean different things. B...

GRDDL is out, providing a mechanism for providing instructions to convert documents on the web into RDF . In short, GRDDL allows you to link an XSLT transform to your XHTML page, which converts the XHTML into an RDF document. For more information, start at the GRDDL Primer . (The irony is that while you can use XSLT to convert into RDF, you can't ever use XSLT to convert RDF into something else with complete certainly because RDF/XML output is nondeterministic.) The primer includes a few examples of using SPARQL to query the RDF document generated by a GRDDL transform. Here's an example from the primer: PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX rev: <http://www.purl.org/stuff/rev#> PREFIX vcard: <http://www.w3.org/2006/vcard/ns#> PREFIX dc: <http://purl.org/dc/elements/1.1/> PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT DISTINCT ?rating ?name ?region ?hotelname FROM <http://www.w3.org/TR/grddl-primer/hotel-data.rdf>...

e is a stack for the data web . Not only is this all in Ruby and uses RDF , but it's some of the most bare code I've seen in a while. You had me at "data web". And +10 for using the file system as a data store instead of a database.

I was very happy to see that Tim Berners-Lee publishes the WWW2007 conference program as RDF . Albeit, a little late, but this exactly the type of grass roots raw RDF data generation we need to build out the semantic web. And who better to show us how it's done than the people who are preaching the semantic web? Thanks, TBL! I'm hoping this kind of pragmatic data generation will show us A) it's not that hard and B) some best practices for putting real life data on the web as RDF.

Dabble DB has completely blown me away. Dabble DB is like Club Med for your data. You want your data to get a massage while sipping a Mai Tai on the beach, you got it. Your data will get the five star treatment at Dabble DB. So everyone is talking about Web 3.0 , AKA the Web of Data, AKA the Semantic Web . Those visions are all well and good, and I do believe we'll see a Data Centric Web soon. But if there's a Web of Data, that must mean you've got Data on the Web. What? Your data is buried in some SQL Server database on the company LAN? That doesn't sound very webby to me. And you're building all these custom, one-off, Visual Basic apps or Excel macros manage your data? Tisk, tisk. So not webby. This is where Dabble DB comes in. Not only does it provide a very slick, dripping with AJAX interface for you to import and manage your data, it's a *very* smart interface. Normal muggles (Haven't read Harry Potter? Whaaaa?) can easily use Dabble DB ...

Oracle 11g will gain native OWL support. From the article: > (2) Native OWL inferencing (for an OWL subset that includes property characteristics, class comparisons, proprety comparisons, individual comparions and class expressions) [New API] Way to go, Oracle! I've always had a soft spot for Oracle's RDF support. The way that you can blend RDF data sets and traditional relational data sets in the same query helps to deploy RDF slowly but surely. Not to mention that Oracle has already solved all the main problems that a RDBMS should solve (like ACID compliance, backup and recovery, strong security, wide developer toolset) makes Oracle's RDF support (and soon OWL) a strong contender for RDF data stores.

So some guy writes why the semantic web will fail and ends up on Slashdot . How slashdot picks their articles, I'll never know. The article is pure opinion and guesswork (as all predictions seem to be), and it's perfectly OK for this guy to blog his opinions. I'm not going to argue that the semantic web (that's *small s* semantic) will succeed, although I think it will prove useful in a large sense in some form, even if that form isn't RDF. I think what's really telling about the doom and gloom post is that the marketing message of the semantic web has failed. For example, a quote from the blog post: > The Semantic Web will never work because it depends on businesses working together, on them cooperating Where, in all of the W3C's semantic web literature does it says that companies must work together for the semantic web to succeed? I think this is one of the biggest misinterpretations about the semantic web. For some reason, people think that the s...

Jim Hendler asks so where are the agents? More specifically, I'd like to ask What do we need before agents can be deployed? Let me define what I believe an agent is by looking at what it would do for me. I think a software agent is a program that can be given a set of rules and able to seek out data that satisfies those rules. Agents are different from other sets of software that can answer queries in that Agents would be able to reason about the world and would be capable of acting towards its goal(s) over a long period of time. These agents would act without direct human control, which is especially import if the task would take some time to complete. Given that definition of an Agent, I revisit the question: What do we need before agents can be deployed? Because Agents are task focused, we need a way to define the task in such a way that the Agent understands it. I can imagine simple use cases like "Schedule my dentist appointment every six months. Of course, make ...

baetle is an ontology for software bugs and bug tracking systems. Henry Story has opened the baetle project on Google Code . baetle is an effort to standardize a view into the software bug tracking world. There are a kazillion bug tracking systems out there . Heck, see for yourself . So what's a use case for being able to have a consistent view into bugs and issues across all thoses systems? For one, you could query one system just like another system. Another use case might be if your enterprise runs and maintains multiple different bug tracking systems, and you need to query across all of them. Hmm, sounds like a Data Warehouse, doesn't it? Multiple systems combined and filtered into one cohesive view for reporting and querying. Ontologies allowing for a way to combine and filter all those data sources. SPARQL for all that querying. So is Ontologies and SPARQL the new ETL ?

Querying the web might get a bit easier, with the union of SPARQL directly with HTTP. TripleSoup , a promising proposal at Apache , aims to expose Triple Stores (RDF databases) directly via HTTP. This reminds me of URIQA , which is an effort to provide native HTTP methods for accessing metadata about a certain resource. URIQA was interesting because it allows you to say MGET /foo HTTP/1.1 which means "Retrieve the metadata for resource `/foo`" It looks like TripleSoup is a bit different, in that the URI in the request methods is some type of application. TripleSoup seems to be a gateway directly into the triple store, whereas URIQA masks the concept of talking to the triple store. In URIQA, it looks like the triple store *is* the server you are connecting to. With TripleSoup, the triple store is located at the URI you are sending requests to. URIQA's advantage is that you don't need to know the URI to the application or triple store, you can just send an MGE...

Thinking about OpenID , the next step is obviously a way to integrate trust into an identity. The first question people will want to ask, I believe, is, "Is this person a spammer?" (Insert your own definition for spammer here, but typically this will mean "Will this person use this site/application/service for the originally intended purpose and will abide by the policies and rules of the site/application/serivce?") Now that it seems like everyone is getting on board with OpenID (AOL, digg, Technorati, LiveJournal, even Microsoft), there are a lot of identities swimming around. This is a Good Thing. However, nothing stops a spammer or Bad Guy from creating their own OpenID. This is also a Good Thing, because OpenID is only there to verify the identity. Other technologies and layers are then free to add in Trust. There's a lot of built up trust information out on the web if we can just get to it. Think about all the hard earned feedback profiles and rankin...

Bill de hÓra rightfully proposes that it would be very interesting to augment Planet software with scanning tools extracting RDF from uF and republishing the RDF for SPARQL queries or as RSS1.0 . I've often wondered why PlanetRDF.com , or something like it, doesn't use semantic technologies to pull blog posts from the blogosphere that are related to, or about, semantic web technologies, RDF, OWL, etc. What's stopping this from happening? Isn't the great Use Case of the semantic web to allow for more exact searches of web information? (I'm not specifically talking about Google knowing the difference between an apple (the fruit) and Apple (the computer company)) Why can't I say, "Create a Planet of all blog posts that are about the Semantic Web. Oh, and use only posts from authors who are known by Dave Beckett, Danny Ayers, and those that work with Jim Hendler." Wouldn't that be neat? Of course, there is benefit in a human edited Planet RDF. But...

Lee rightly asks Who loves RDF/XML? to which I reply, "No one that I know." Is RDF/XML the core of the semantic web? I think it's easy to argue that the W3C thinks of RDF as the core of the semantic web. The web is made up of documents. Those documents are serializations (representations) or resources. The W3C's Recommended way of serializing RDF is RDF/XML. Therefore, if RDF is the core of the semantic web and it has to be shuffled around the internets, I think it's also say to assume that the Recommended way to do that is RDF/XML.