[osis-core] reference systems: my thoughts

[Harry Plantinga]

> 3. Cf., Todd's latest post on reference systems. I personally 
> like the 
> current proposal but realize we need something that is largely 
> transparent for 95%+ of the users, at least in this release. 
> I will try 
> to post something later today outlining (without a lot of 
> quoted texts 
> from other posts) where I think we are on this issue.

OK. I hesitate to post, for fear I'll muddy the water rather than
clear it, but since there are two different systems in the table
I will post my thinking on reference systems.

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First, a general commetn. When one are only thinking about the bible,
one tends to come up with a solution that is optimal only for the bible.
But if we also want to encode other works, let's think about the more
general problem.  Say you've got 100s or 1000s of books to encode, most
of which will be different, but there will be a few instances of two or
more editions of the same work, e.g. augustine_confessions.


Principles.

1.  A reference system doesn't exist by itself; it's only a reference
system by virtue of being used in some particular edition of some book.
(We've been talking about biblical reference systems by themselves, but
even in this case I think it's true - we talk about the KJV reference
system, for example.)

2.  When we refer to a work, we may wish to refer in general to all
editions of the work (Thomas a Kempis' The Imitation of Christ) or to a
specific edition (New York: Mentor Books, 1957).  

Some examples of the way we typically make such references: (a) The
Imitation of Christ, book II, chapter 20. (b) Calvin's Institutes,
III.xx.4. (c) Berkouwer's Man: the Image of God (Eerdmans, 1962), p.
170.  But we don't want to have to write all that stuff for each of
several references for a document.  Thus, a single work specification
and some shorthand way of referring to the work. Work identifiers may be
generic or edition specific.  But we always refer to a book or work, not
a reference system. When we make a generic reference, it is always to
different editions of the same work, e.g. different translations of the
bible.

3.  A reference to a work will identify the work (whether generic or
edition-specific) and give the location reference within the work.  If
the work is identified generically, there must be an understood default
reference system, or the reference system must be identified. It doesn't
make sense to refer to a specific location in a class of works that
don't have compatible reference systems. (E.g. Chapter1 of any book
written by Augustine.) 

Since reference systems are defined by their use in a particular edition
of a work, one normally specifies a reference system by  the system by
mentioning the edition of a work  (e.g. not just Augustine's
Confessions, but Pusey's translation of Augustine's confessions).

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How should this work for OSIS?

I propose the following.  Actually, as I understand the situation, Steve
and I both think the group had already decided on the namespace-like
prefix as work identifier some time ago.  The dropping of the notion of
"reference system" except as embodied in a particular edition of a
particular work is new.

Works are identified in a <work osisWork="conf"> element.  They may be
identified generically (Augustine's Confessions or bible.lxx.*.en) or
specifically (Augustine's confessions, SPCK 1912 or ISBN 12-345-67890x
or OSIS augustine_confessions.spck1912). Later references to the work
use namespace-like syntax: conf:X.3

Reference systems (Bible.KJV, Augustine_Confessions.spck1912) are
defined when a work with that workID is created. Reference systems are
identified by giving the osisID of the work that embodies it, e.g.
Bible.KJV. So Bible.KJV is really an external OSIS work identifier,
which implements a reference system.

Works can only use the "." in the OSIS work identifier when a
translation has been defined between the reference systems.  Thus,
someone will create a "Bible" document that embodies the OSIS default
bible reference system.  Bible.KJV will be another document, and it must
contain the Bible.KJV reference system as well as ties back to the Bible
reference system which would allow transformation between the reference
systems.

If one wishes to make a generic reference to augustine's confessions,
and even if there are two different common reference systems, say
spck1912 (default) and eerdmans1985, one still doesn't need to say which
system is in use.  The <work> element may connect osisWork="conf" to
augustine_confessions or augustine_confessions.spck1912, but in any
case, the reference system to use will be clear and the transformation
available if needed.
- if conf is tied to augustine_confessions.spck1912, then conf:X.3 will
use the reference system of that osisWork.
- if conf is tied to augustine_confessions, then conf:X.3 will use the
reference system of that osisWork, which would be the default edition of
augustine's confessions.

In 99% of the cases, no mention need be made of the reference system.
That is only necessary when one wants to "cross over" reference systems,
i.e. refer to one edition in the reference system of another. This would
be done by specifying the osisWork ID of the document embodying the
reference system.  So, 

<work workID="conf">
  <title>Augustine's Confessions</title>
  <identifier
type="OSIS">augustine_confessions.eerdmans1985</identifier>
  <refSystem>augustine_confessions.speck1912</refSystem>
</work>

Thus in this proposal we would drop the <refSystems> and <refSystem>
elements. By this proposal we would not be able to
augustine_confessions.xyzzy as a reference system unless there is an
OSIS version of that document. It seems to me that it doesn't make sense
to use a reference system unless it is defined as an OSIS document.
Otherwise people may use different syntax, etc.

What about Todd's objection that people aren't going to want to
understand the whole reference system thing for simple bible references?

- in this proposal you only have to mention reference systems when you
refer to one edition in the reference system of another, so most use
will never have to deal with reference systems separately.
- if you want to refer to the bible in the default reference system,
just say Bible:Matt.1.1. Or make Bible: the default reference system. 

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Specific syntax proposals to follow.
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-Harry