RDF123 Makes Generating Flexible RDF a Snap

UMBC’s Ebiquity Program Creates Another Great Tool

In a strange coincidence, I encountered a new project called RDF123 from UMBC’s Ebiquity program a few days back while researching ways to more easily create RDF specifications. (I was looking in the context of easier ways to test out variations of the UMBEL ontology.) I put in on my to-do list for testing, use and a possible review.

Then, this morning, I saw that Tim Finin had posted up a more formal announcement of the project, including a demo of converting my own Sweet Tools to RDF using the very same tool! Thanks, Tim, and also for accelerating my attention on this. Folks, we have another winner!

RDF123, developed by Lushan Han with funding from NSF [1], improves upon earlier efforts from the University of Maryland’s Mindswap lab, which had developed Excel2RDF and the more flexible ConvertToRDF a number of years back. Unlike RDF123, these other tools were limited to creating an instance of a given class for each row in the spreadsheet. RDF123, on the other hand, allows users to define mappings to arbitrary graphs and different templates by row.

It is curious why so little work has been done on spreadsheets as an input and specification mechanism for RDF given the huge use and ubiquity (pun on purpose!) of the format. According to the Ebiquity technical report [1], Topbraid Composer has a spreadsheet utility (one that I have not tested) and there is a new plug-in for Protégé version 4.0 from Jay Kola that was also on my to-do list for testing (which requires upgrading to the beta version of Protégé) that has support for imports of OWL and RDF Schema.

I have also been working with the Linking Open Data group at the W3C regarding converting the Sweet Tools listing to RDF, and have indeed had a RDF/XML listing available for quite some time [2]. You may want to compare this version with the N3 version produced by RDF123 [3]. The specification for creating this RDF123 file, also in N3 format, is really quite simple:

@prefix d: <http://spreadsheets.google.com/feeds/list/o15870720903820235800 etc., etc.> .
@prefix mkbm: <https://www.mkbergman.com/> .
@prefix exhibit: <http://simile.mit.edu/2006/11/exhibit#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix : <#> .
@prefix e: <http://spreadsheets.google.com/feeds/list/o15870720903820235800 etc., etc.> .

<Ex:e+$1>
  a exhibit:Item ;
  rdfs:label "Ex:$1" ;
  exhibit:origin "Ex:mkbm+'#'+$1^^string" ;
  d:Category "Ex:$5" ;
  d:Existing "Ex:$7" ;
  d:FOSS "Ex:$4" ;
  d:Language "Ex:$6" ;
  d:Posted "Ex:$8" ;
  d:URL "Ex:$2^^string" ;
  d:Updated "Ex:$9" ;
  d:description "Ex:$3" ;
  d:thumbnail "Ex:@If($10='';'';mkbm+@Substr($10,12,@Sub(@Length($10),4)))^^string" .

The UMBC approach is somewhat like GRDDL for converting other formats to RDF, but is more direct by bypassing the need to first convert the spreadsheet to XML and then transform with XSLT. This means updates can be automatic, and the difficulty of writing XSLT is replaced itself with a simple notation as above for properly replacing label names.

RDF123 has the option of two interfaces in its four versions. The first interface, used by the application versions, is a graphical interface that allows users to create their mapping in an intuitive manner. The second is a Web service that takes as input a combined URL string to a Google spreadsheet or CSV file and an RDF123 map and output specification [3].

The four versions of the software are the:

• Windows application
• Linux application
• Java application
• and, an online Web service.

RDF123 is a tremendous addition to the RDF tools base, and one with promise for further development for easy use by standard users (non-developers). Thanks NSF, UMBC and Lushan!

And, Thanks Josh for the Census RDF

Along with last week’s tremendous announcement by Josh Tauberer for making 2000 US Census data available as nearly 1 billion RDF triples, this dog week of August in fact has proven to be a stellar one on the RDF front! These two events should help promote an explosion of RDF in numeric data.

[1] Lushan Han, Tim Finin, Cynthia Parr, Joel Sachs, and Anupam Joshi, RDF123: A Mechanism to Translate Spreadsheets to RDF, Technical Report from the Computer Science and Electrical Engineering Dept., University of Maryland, Baltimore County, August 2007, 17 pp. See http://ebiquity.umbc.edu/paper/html/id/368/RDF123-a-mechanism-to-translate-spreadsheets-to-RDF; also, a PDF version of the report is available. The effort was supported by a grant from the National Science Foundation.

[2] This version was created using Exhibit, the lightweight data publishing framework for Sweet Tools. It allows RDF/XML to be copied from the online Exhibit, though it has a few encoding issues, which required the manual adjustments to produce valid RDF/XML. A better RDF export service is apparently in the works for Exhibit version 2.0, slated for soon release.

[3] N3 stands for Notation 3 and is a more easily read serialization of RDF. For direct comparison with my native RDF/XML, you can convert the N3 file at RDFabout.com. Alternatively, you can directly create the RDF/XML output with the slightly different instructions to the online service of: http://rdf123.umbc.edu/server/?src=http://spreadsheets.google.com/pub?key=pGFSSSZMgQNxIJUCX6VO3Ww&map=http://rdf123.umbc.edu/map/demo1.N3&out=XML; note the last statement changing the output format from N3 to XML. Also note the UMBC service address, followed by the spreadsheet address, followed by the specification address (the listing of which is shown above), then ending with the output form. This RDF/XML output validates with the W3C’s RDF validation service, unlike the original RDF/XML created from Sweet Tools that had some encoding issues that required the manual fixing.