I recently did a review of options for creating visual representations of RDF data. I didn’t just want a general visualization tool, but something that understood RDF enough to represent class instances and literal values differently. I will emphasize instances because several tools out there can read RDF schema or ontologies and create a visualization of classes and their relationships and potential properties, but I want to see instances with their property values.
In my last blog entry I discussed various ways that different RDF datasets assign human-readable labels to resources, with the rdfs:label
property being at the center of them all. I mentioned how schema.org doesn’t use rdfs:label
but its own equivalent of that, schema:name
, which its schema declares as a subproperty of rdfs:label
. Since I wrote that, Fan Li pointed out that Facebook’s Open Graph protocol also has their own equivalent: og:title
, which you can see used in the HTML…
First, reviewing some basics before I discuss the edge cases: resources in RDF are represented by URIs, and the spelling of a given URI often provides no clues about what the URI represents. For example, you wouldn’t know from looking at http://www.wikidata.org/entity/Q144
that it represents “dog” as a Wikipedia topic. (We’ll see below that this is a for a good reason.)
The following blog entries give a brief introduction to the RDF data model, the most important of the other W3C standards that build on it, and what people do with those standards:
I recently wondered “could I run a Python script that includes the rdflib library on my Samsung Android phone?” Five minutes later, I was doing it, and about three of those minutes were spent installing Python.
OriginTrail is doing one of the most interesting combinations of blockchain technology and RDF that I have seen. In November I spoke with CTO and co-founder Branimir Rakić.
I have always loved the website Learn X in Y minutes, which provides short crash courses in several dozen programming languages plus additional topics such as set theory and git. Its home page tells us “Take a whirlwind tour of your next favorite language”; I’ll bet it’s especially popular with applicants on their way to job interviews where languages that are new to them are in the job description.