The best interoperability is interoperability between standards. I mean it’s one thing for you and I to agree to use the same standard in the same way to do the same thing, but what if we are doing slightly different things? What if Dublin Core is right for you, but schema.org is right for me–does that mean we can’t exchange data? That would be a shame, as one standard to rule them all isn’t a viable solution. This has been exercising me through a couple of projects that I have worked on recently, and what I’ll show here is demo based on the ideas from one of these (The T3 Data Ecosystem Mapping Project) applied to another where learning resource metadata is available in many formats and desired in others. In this post I focus on metadata available as IEEE Learning Object Metadata (LOM) but wanted in either schema.org or DCAT.
Tag Archives: semantic technologies
JSON Schema for JSON-LD
I’ve been working recently on definining RDF application profiles, defining specifications in JSON-Schema, and converting specifications from a JSON Schema to an RDF representation. This has lead to me thinking about, and having conversations with people about whether JSON Schema can be used to define and validate JSON-LD. I think the answer is a qualified “yes”. Here’s a proof of concept; do me a favour and let me know if you think it is wrong.
Mapping learning resources to curricula in RDF
Some personal reflections on relating educational content to curriculum frameworks prompted by some conversation about the Oak National Academy (a broad curriculum of online material available to schools, based on the English national curriculum), and OEH-Linked-Frameworks (an RDF tool for visualizing German educational frameworks). It draws heavily on the BBC curriculum ontology (by Zoe Rose, I think). I’m thinking about these with respect to work I have been involved in such as K12-OCX and LRMI.
If you want to know why you would do this, you might want to skip ahead and read the “so what?” section first. But in brief: representing curriculum frameworks in a standard, machine-readable way, and mapping curriculum materials to that, would help when sharing learning resources.
Inclusion of Educational and Occupational Credentials in schema.org
The new terms developed by the EOCred community group that I chaired were added to the pending area in the April 2019 release of schema.org. This marks a natural endpoint for this round of the community group’s work. You can see most of the outcome under EducationalOccupationalCredential. As it says, these terms are now “proposed for full integration into Schema.org, pending implementation feedback and adoption from applications and websites”. I am pretty pleased with this outcome.
Please use these terms widely where you wish to meet the use cases outlined in the previous post, and feel free to use the EOCred group to discuss any issues that arise from implementation and adoption.
My own attention is moving on the Talent Marketplace Signalling community group which is just kicking off (as well as continuing with LRMI and some discussions around Courses that I am having). One early outcome for me from this is a picture of how I see Talent Signalling requiring all these linked together:
Using wikidata for linked data WordPress indexes
A while back I wrote about getting data from wikidata into a WordPress custom taxonomy. Shortly thereafter Alex Stinson said some nice things about it:
@philbarker This is a really cool use of @Wikidata: https://t.co/vK82OrWOG2 ! Is this something that could be made an extension/tool for wordpress? seems like a powerful way to connect Wikidata to more web content cc’ @Auregann @nightrose @johl
— Alex Stinson (@sadads) January 19, 2018
and as a result that post got a little attention.
Well, I have now a working prototype plugin which is somewhat more general purpose than my first attempt. Continue reading
Getting data from wikidata into WordPress custom taxonomy
[there is an update of this work]
I created a custom taxonomy to use as an index of people mentioned. I wanted it to work nicely as linked data, and so wanted each term in it to refer to the wikidata identifier for the person mentioned. Then I thought, why not get the data for the terms from wikidata?
Wikidata driven timeline
I have been to a couple of wikidata workshops recently, both involving Ewan McAndrew; between which I read Christine de Pizan‘s Book of the City of Ladies(*). Christine de Pizan is described as one of the first women in Europe to earn her living as a writer, which made me wonder what other female writers were around at that time (e.g. Julian of Norwich and, err…). So, at the second of these workshops, I took advantage of Ewan’s expertise, and the additional bonus of Navino Evans cofounder of Histropedia also being there, to create a timeline of medieval European female writers. (By the way, it’s interesting to compare this to Asian female writers–I was interested in Christina de Pizan and wanted to see how she fitted in with others who might have influenced her or attitudes to her, and so didn’t think that Chinese and Japanese writers fitted into the same timeline.)
New publication analysing LRMI metadata on the web
I have a new publication: “Analysing and Improving Embedded Markup of Learning Resources on the Web,” which Stefan Dietze and Davide Taibi have presented at the 2017 International World Wide Web Conference in Perth Australia. I played a minor role in the “analysing” part of this work, the heavy lifting was done by my co-authors. They analysed data from the Common Crawl to identify sites that were using LRMI terms in their schema.org markup. The analysis provides answers to important questions such as: who is using LRMI metadata and which terms are they using? How many resources have been marked up with LRMI metadata? Are the numbers of users growing? What mistakes are being made in implementing LRMI? Continue reading
Three resources for custom metadata in WordPress
When developing WordPress for use as a CMS one approach I have used is to create a custom post type for each type of resource and custom metadata boxes for relevant properties of those types. I’ve used that approach when exploring the possibility of using WordPress as a semantic web platform to edit schema.org metadata, when building course information pages for students and am doing so again in updating some work I did on WordPress as a lightweight repository. Registering a custom post type is pretty straightforward, follow the example in the codex page, I found handling custom metadata boxes a little more difficult. Here are three resources that helped.
Doing it long hand
It’s a few years old, but I found Justin Tadlock’s Smashing Magazine article How To Create Custom Post Meta Boxes In WordPress really useful as a clear and informative tutorial. It was invaluable in understanding how metaboxes work. If I had only wanted one or two simple text custom metadata fields then coding them myself would be an option, but I found a couple of problems. Firstly, I was repeating the same code too many times. Secondly when I thought about wanting to store dates or urls or links to other posts, with suitable user interface elements and data validation, I could see the amount of code needed was only going to increase. So I looked to see whether any better programmers than I had created anything I could use.
Using a helper plugin
I found two plugins that promised to provide a framework to simplify the creation of metaboxes. These are not plugins that provide anything that the end user can see directly, rather they provide functions that can be used in theme an plugin development. They both reduce the work of creating a metabox down to creating an array with the properties you want the metabox to have. They both introduce a dependency on code I cannot maintain, which is something I am always cautious about in using third-party plugins, but it’s much more viable than the alternative of creating such code from scratch and maintaining it myself.
CMB2 is “a metabox, custom fields, and forms library for WordPress that will blow your mind.” It is free and open source, with development hosted on GitHub. It seems quite mature (version 1.0 was in Nov 2013), with a large installation base and decent amount of current activity on github.
Meta Box is “a powerful, professional developer toolkit to create custom meta boxes and custom fields for WordPress.” It too is free and released under GPL2 licence, but there are paid-for extensions (also GPL2 licensed) and I don’t see any open source development (I may not have looked in the right place). Meta box has been around for a couple of years, is regularly updated and has a very large user base. The paid-for extensions give me some hope that the developers have a sustainable business model, but a worry that maybe ‘free’ doesn’t include the one function that at sometime I will really need. Well, developers cannot live on magic beans so I wouldn’t mind paying.
In the end both plugins worked well, but Meta Box allows the creation of custom fields for a link from one post to another, which I didn’t see in CMB2. That’s what I need for a metadata field to say that the author of the book described in one post is a person described in another.
Schema course extension update
This progress update on the work to extend schema.org to support the discovery of any type of educational course is cross-posted from the Schema Course Extension W3C Community Group. If you are interested in this work please head over there.
What aspects of a course can we now describe?
As a result of work so far addressing the use cases that we outlined, we now have answers to the following questions about how to describe courses using schema.org:
-
- How to define something as being about a course or being about an instance of that course
- How to mark up the identifier used by providers to identify their courses
- How to identify a course by provider and name
- How to mark up the subject of a course
- How to identify the location where a course is offered
- How to identify the start and end of an instance of a course, and the times of events that are part of it
- Related to start and end dates of a course, how to specify the duration and amount of time typically required to complete a course
- How to identify the organizations providing and offering courses (and how these two roles may differ).
- How to identify the teacher / instructor of a course (who may or nay not be the creator of the course).
- How to mark up the mode of study or delivery.
- How to identify a course which is a prerequisite of the course being described or to link to or describe other prerequisites.
As with anything in schema.org, many of the answers proposed are not the final word on all the detail required in every case, but they form a solid basis that I think will be adequate in many instances.
What new properties are we proposing?
In short, remarkably few. Many of the aspects of a course can be described in the same way as for other creative works or events. However we did find that we needed to create two new types Course and CourseInstance to identify whether the description related to a course that could be offered at various times or a specific offering or section of that course. We also found the need for three new properties for Course: courseCode, coursePrerequisites and hasCourseInstance; and two new properties for CourseInstance: courseMode and instructor.
There are others under discussion, but I highlight these as proposed because they are being put forward for inclusion in the next release of the schema.org core vocabulary.
More good news: the Google search gallery documentation for developers already includes information on how to provide the most basic info about Courses. This is where we are going 🙂