On Tue, 29 Apr 2003, Phil Barker wrote:
> 1) You say "We do not need to try and answer the question 'What is a
> learning object?' here", however we think that many of the points you
> raise are based assumptions about what a learning object is, and it would
> be as well to spell these out. Specifically, it seems to us that you are
> considering a learning object to be online content which can be moved from
> one environment to another. We're not clear how your requirements would
> relate to books, CD-ROMs or resources like the H.M. Treasury website
> http://www.hm-treasury.gov.uk/
I wasn't intending to specifically limit the scope to digital learning
objects (and I consciously tried to make the requirements generic enough
for all objects - though because of the context I have used the words
'learning object' throughout the text). I agree that the fact that some
learning objects are physical needs to be spelled out.
> We're not objecting limiting the scope of the discussion like
> this--discussion of identifiers within this narrower definition is
> perfectly valid, and very useful. However, many people will want to create
> metadata instances for the type of learning resource listed above (books,
> CD-ROMs, websites) so they will need to know that the issues discussed here
> perhaps aren't relevant to them.
It is worth bearing in mind that some physical learning objects already
have identifiers, e.g. ISBNs for books, but that these, as they stand, may
not meet all the requirements listed.
> 2) "Why do we need identifiers?" is only a part of the rationale behind
> needing this discussion. There is no shortage of identifier schemes: every
> repository has one. The questions which (for us) drives this discussion are
> "Why should we share identifiers?" and "Do we want to minimise the number
> of schemes?". In other words, is anything wrong with the approach possible
> with the LOM of every publisher creating their own scheme [the scheme needs
> a globally unique identifier--less of a problem than each object needing a
> globally unique identifier].
Yup, agreed.
> 3) We've found your use of the word creator in the issues list a little
> confusing. Your use works for institution as a coporate author but we think
> that the issues you outline arise from them acting as the initial publisher
> (ie the first entity to make the resource available) rather than their role
> in creating the resource. We also think that the first of your issues for a
> Learning object respository administrator (Lora) is an issue for the
> initial publisher, while others are issues for Lora when responsible for
> distribution/retail/"secondary publishing" activities.
> We also think that there will be an important issue around allocation of
> IDs to existing (legacy?) objects, which will concern publishers/Lora.
I had intended 'creator' to mean the party (typically an individual) that
created the learning object. An institution that publishes the LO on it's
Web site is acting as a (very unstructured) learning object repository.
> 4) Another issues for resolver system administrators is: what info needs to
> be stored and what info needs to be returned to the user? ID and location
> are the bare minimum for a resolver to work. Status of the object might be
> useful (ie is it still available).
OK, fair point.
> The following relate to the Learning object identifier requirements section:
>
> 5) I'm interested to know if these are radically different to the
> requirements for digital objects other than LOs.
I don't think so. (I originally wrote part of this text as part of an
ongoing discussion, on another list, about identifiers for e-government
resources).
However, discussion of 'identifiers' often gets wrapped in wider
discussion about 'preservation', where 'long term' tends to mean hundreds
of years rather than tens of years and that does have a drastic impact on
your requirements and the kinds of solutions you look at.
> 6) How important is it that identifiers per se should be usable in Web
> browsers? Isn't the requirement that resolver services should be usable
> through web browsers? The DOI 10.1000/186 itself is not actionable in a web
> browser, but doi:10.1000/186 is actionable with the CNRI Handle System
> Resolver plug-in (as you say, not an ideal situation--presumably it can be
> made actionable through http if a link to a suitable resolver is used).
Well, I think it is important - but you are allowed to disagree! ;-)
I think it is important because, in practice, identifiers are going to be
used in the various kinds of transactions that occur between Web servers
and Web browsers - and in that context, the only useful 'identifier' is
one that works like a 'locator'. IMHO.
> 7) Could you explain your thinking behind requirement 9, identifers should
> be URI compliant? Do you mean they should be in the form of URIs or that it
> should be possible to include them in URIs (ie should not contain awkward
> characters like spaces, ampersands etc).
They should be valid URIs. '10.1000/18' isn't OK. 'doi:10.1000/18' is
OK. But 'http://purl.org/poi/doi:10.1000/18' is even better because of
the answer to 6) above.
> 8) In requirement 7, "they should be assignable in devolved environments",
> your reasoning here is clear (we think) but do you really mean "without
> reference to a central service"? Don't PURL, DOI, URL all rely on central
> services at some point and so anything based on these would? Do you mean
> that a publisher should not have to go to a central service repeatedly for
> each and every new identifier (but they might have to go to a central
> service for a scheme identifier, for an identifier pre-/post-fix, or for
> blocks of identifers)?
Yes to the second part. Once I have been delegated a part of the PURL or
DOI space, then I can assign a PURL or DOI (within my space) without
checking back against the PURL or Handle server to make sure that someone
else hasn't already assigned it. Just as I can assign a URL under
http://www.rdn.ac.uk/ without needing to check with anyone outside the
RDN.
Andy
--
Distributed Systems, UKOLN, University of Bath, Bath, BA2 7AY, UK
http://www.ukoln.ac.uk/ukoln/staff/a.powell +44 1225 383933
Resource Discovery Network http://www.rdn.ac.uk/
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