EOCred: Identifying subtypes of credential

Hello again, moving on to the next requirement for describing 
Educational and Occupational Credentials in schema.org: I suggest we 
look at how to identify the subtypes of these credentials.

The use case for this 
<https://www.w3.org/community/eocred-schema/wiki/Use_Cases#Identify_subtypes_of_credential> 
gives examples of "degree" "certificate" "badge". I know there are about 
20 others from the Credential Engines' CTDL 
<http://credreg.net/ctdl/handbook#creds>. Most countries will have their 
own types of EO Credential, for example in Scotland we have  National 
Qualifications, HNDs, HNCs, SVQs, IVAs, PDAs, DipHEs, CertHEs and many 
more. Other countries will be similar. Furthermore, the types of 
qualification on offer changes over time.

In short, the number of types is we need to consider is vast and varied. 
So, while CTDL has subclasses of its Credential class for each of its 
distinct types, that is not a practical solution for wider use. Even if 
we could reduce the number and variety of types, I think it would add 
too many subclasses to the schema.org hierarchy, given that most of the 
subtypes would have no unique properties.

The alternative is for EducationalOccupationalCredential to have a 
property which records the type of credential. With a nod to Richard's 
point that much of what we do is applicable to generic credentials, I 
propose we call this credentialType.

The basic range for credentialType would be text, and I think we should 
explicitly allow this. We could stop here.

In an ideal world there would be controlled vocabulary for naming the 
credentialTypes. However, I a single controlled vocabulary of all the 
precise types is not feasible, and I think that producing a vocabulary 
that classifies these types into categories like "certificate" would be 
very difficult and the results would be very imprecise. We should, 
however try to facilitate the use of local controlled vocabularies. This 
is where we reach the edge of what currently possible in schema.org.

Options for facilitating the use of local controlled vocabularies of 
credential type:

1, allow a URL to link to a controlled value / external enumeration.

2, allow alignmentObjects to provide information about the 
credentialType as if credential types were educational frameworks

3, use the developing schema.org type that is currently called 
CategoryCode <http://pending.schema.org/CategoryCode>, but which is 
proposed to be changed to TermDefinition
<https://github.com/schemaorg/schemaorg/issues/1775>

In my view: 1 is too vague (who knows what will be at the end of the 
URL), 2 stretches the alignmentObject somewhat, and 3 is the best option 
for the long run. An example using option 3 would look something like:

{
   "@type": "EducationalOccupationalCredential",
   "name" : "HNC Facilities Management",
   "credentialType": {
     "@type" : "TermDefinition",
     "name" : "Higher National Certificate",
     "termCode" : "HNC",
     "inDefinedTermSet" : "SQA Qualifications" //should be a URL or 
DefinedTermSet object
   }
}

What do you think? Too complicated, maybe? Am I overthinking the 
problem? Are there enough well-constructed sets of terms describing 
credential types for it to be worth trying to accommodate anything other 
than text values?

Phil

-- 

Phil Barker <http://people.pjjk.net/phil>. http://people.pjjk.net/phil
PJJK Limited <https://www.pjjk.co.uk>: technology to enhance learning; 
information systems for education.
CETIS LLP: a cooperative consultancy for innovation in education technology.

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