Notes from TEI Meeting on Element Classes

This was a meeting of the subset of the TEI Council charged by the complete Council to examine and improve the TEI class system.

The meeting was held at the University Club at Oxford University. Thanks are extended to the members from Oxford (LB, JC, SR) for their efforts in organizing the meeting, and to SR for providing home-grown apples.

Meeting started with SB, LB, JC, SR, JW, CW at 09-26 09:25; LR arrived at 12:04; broke at ~17:00; continued 09-27 starting at 09:04; ended at 16:57. A subset (SB, JC, SR, CW) met the following morning (09-28) from 09:30 to 12:25 and worked on developing the guidelines for naming model classes.

Preliminaries

CW chaired the meeting; notes of decisions taken were recorded by SB, LB, and JC. This document is based upon SB's notes with some additions from JC's, revised by LB.

First, the agenda was reviewed, and printed copies of ED W 84 were handed out. It was quickly realized that the current ED W 84 was insufficient for our purposes, so SR updated it so that part 1 also included a column for the class membership of each element. This new version was placed on the TEI website, and projected for the group.

LB provided a quick overview of how classes work, defining attribute, model, and content classes as (respectively) elements which share a set of attributes, which occur in the same places in content models, and which share the same content model.

General Decisions.

We began by reviewing several general questions circulated before the meeting.

• We agreed to distinguish attribute classes from model classes. (I.e., no more both classes, and the naming scheme should reflect the different purposes.)

We discussed whether or not we wanted another kind of class in order to group elements that share a content model ("content classes"), or for syntactic sugar issues. The following example was used to help anchor this question:

+ If we had a model class X w/ members A and B. + A is a member of X, has content D* + thus there exists a content class DSTAR of which A is a member + DSTAR has members A and others + Now I want to change A so that it has E also: E|D* + have I removed A from DSTAR, or have I changed DSTAR?We also considered whether it was helpful to divide classes into semantic and structural classes, noting that all current semantic classes are required to be subclasses of structural ones -- a semantic class such as tei.edit cannot combine elements which are members of different structural classes (say tei.phrase and tei.chunk). We decided that, at least for now, we would consider only attribute and model classes, although recognizing the potential usefulness of the content class concept.

• We affirmed that although different modules may extend membership of classes, the TEI class namespace is global. Consequently, all TEI classes are declared in the same module (at present, core, but possibly textstructure).

• We developed three criteria for an element to directly reference elements instead of only classes in its content model.

  • the content does not already appear in some other TEI element, and we deem it unlikely a customizer will want to use it in an added element; or
  • we deem it very unlikely that a customizer will want to add other child elements to the content model; or
  • the content model includes occurrence indicators, or sequence markers making it more complex than a simple starred alternation of elements (in which case, it should probably be expressed as a macro).Because attribute classes are global, it makes no sense for the same attribute to be declared by more than one attribute class, unless, we can be very sure that no particular element would want to be members of both classes.

• We agreed that greater use of classes was unlikely to result in significantly looser content models than those already in place. We also noted the desirability of making explicit constraints (beyond the content model) currently represented only by prose.

A constraint element as a child of

elementSpec might be needed to do this, rather than (as at present) including them in the general

remarks element. It might also contain Schematron code.

We discussed putting note into tei.Incl but decided not to, based on argument that

• it can be a pain to process
• may cause content model problems (would not be able to have a div of only

notes; would need to fix lots of content models)

• the existing note element represents both the content of a note and its point of attachment. It might be good practice to separate the two functions: in this case, the point of attachment would be represented by an

anchor, and anchor is already a member of

tei.incl

It was noted that the last argument implies a need for specific recommendations on how the anchoring element and the note should be linked (e.g., what the value of type should be).

Participants were reminded that mixing leaf and non-leaf nodes in a single class is generally frowned upon.

We agreed to the rule that if S is a sub-class of C and element E is a member of S then it cannot also be a member of C.

Specific Decisions on Classes

In going through the element list, the following specific changes and recommendations were agreed upon.

• move addrLine into tei.addrPart, and change

address content model accordingly: ( tei.Incl*, ( tei.addrPart, tei.Incl* )+ )

• add the elements referenced by macro.glossSeq into a new class tei.glossing; redefine macro.glossSeq to reference this class
• remove analytic, monogr, and imprint from tei.biblPart
• new class tei.resp contains author,

editor, and respStmt, so that threesome can be factored out of various places ( tei.biblPart, analytic, monogr ×3, titleStmt)

• new class, tei.biblPhrases containing those phrase level elements which should be available within bibl ( title,

date, dateRange): this new class should be a subclass of tei.biblPart. Content model of bibl should reference only tei.biblPart. See email discussion of 1 oct 05

• need a new class, tei.biblBoxes has members

bibl[Struct|Item|Full], many if not all references to bibl should be to new class. — but tei.bibl already does this.

• factor out repeating parts of the fileDesc and biblFull content model to a macro macro.fileDesc. I.e.,
  • macro.fileDesc = titleStmt, editionStmt?, extent?, publicationStmt, seriesStmt?, notesStmt?
  • fileDesc.content = macro.fileDesc, sourceDesc+
  • biblFull.content = macro.fileDesc, sourceDesc*
• change name of tei.refsys to tei.refSys.
• new class, tei.citable that currently contains only

quote, and is referred to instead of q | quote in content of

cit: cit.content = ( tei.citable | tei.bibl | tei.loc | tei.Incl )+

• change the content model of all various non-empty members of tei.edit except choice, to macro.paraContent. The list is add, app, corr,

damage, del, orig, reg, restore,

sic, supplied, and unclear.

• tei.data should reference tei.date, thus remove date, dateRange, and dateStruct from it; i.e. tei.data = ( abbr | address | tei.date | dimensions | eg | egXML | expan | geogName | lang | measure | name | num | orgName | persName | placeName | rs | time | timeRange | timeStruct ) (But note that more reductions should occur to this class later.)
• move abbr and expan from tei.data to

tei.edit

• move gap into tei.intervention, removing its

resp

• make macro.glossSeq (or tei.glossing) the content for all those elements that used to have desc (i.e., certainty, event,

gap, join, joinGrp, kinesic, relation,

respons, and restore)

• headItem and headLabel should not become a class; they may be removed during a reconsideration of the content model of list
• define new tei.imprint class for current children of imprint (pubPlace | publisher | date | biblScope ); factor them out of imprint, which becomes ( tei.imprint, tei.Incl* )+ (note that this model requires an element from tei.imprint, which the previous did not); remove imprint from

tei.biblPart and make the content model of bibl reference tei.imprint

• Remove indexTerm element, replacing it by

term within index; add sortKey to term. (yes, this gives target and cRef to the term in an index) (no, we don't know where the gloss that the target points to goes).

• move label from tei.lists to tei.inter and tei.common.
• new class, tei.metricalCompents … we did not decide whether this class contains only l or both l and lg, or references to two other classes, one for potentially recursive (e.g. lg) and one for non-recursive components (e.g. l). This class is referenced as the content model of lg; LR argued that the potential recursion should not be hidden.
• change content models of list and listBibl so that head is replaced by tei.divtop; also add tei.divbot at the end. E.g., ( tei.divtop | tei.Incl )*, ... ( tei.divbot | tei.Incl )*
• take measure out of tei.names, remember to change example in Guidelines addendum — all examples with key or reg are in CO/co.odd or CO/measure.odd
• new attribute class tei.measured to contain unit, quantity, commodity (A different name is needed to avoid confusion with the existing tei.measured class defined for manuscript description)
• factor persName and orgName, out of tei.naming into tei.agent (which becomes a subclass of

tei.naming), and change content of respStmt accordingly: ( ( tei.agent, resp ) | ( resp, tei.agent ) ), ( tei.agent | resp )*

• factor p elements out passim in favour of reference to tei.paragraph, always putting tei.paragraph first in the content model
• Class tei.citable needs to be a subclass of msItemPart (and possibly other elements currently directly referencing this class need similar treatment, e.g. making

tei.bibl )

• make choice content model ( seg | choice | tei.choosable )*, removing choice and seg from tei.chooseable, thus allowing it to be a pure subclass of tei.edit
• new class tei.spComponent used only in sp, only current member is stage; thus content of sp becomes ... (( tei.paragraph | tei.metricalComponent | lg | tei.segment | tei.spComponent ), tei.Incl* )+
• move ab out of tei.segment into tei.paragraph
• add time, timeRange (if kept), and timeStruct to tei.date (perhaps rename to tei.temporal)
• scriptStmt, sourceDesc, taxonomy, and broadcast need to refer to tei.bibl instead of directly to its elements
• rename tei.front to tei.extraBodyDiv and tei.fmchunk to tei.extraBodyChunk, but with something other than extraBody to indicate that this is stuff which can appear either at the front or the back. The content of front and back should be the same: boiling down to something akin to ( tei.extraBodyChunk | tei.chunk )*, ( tei.extraBodyDiv | div-stuff-here )+
• transform the repetitive parts of

body content model into macros (and consider ways of abolishing numbered divs)

• define new class tei.bookends with members byline | dateline | epigraph | salute | signed as content of closer and opener; factor these out of divtop and divbot
• put all the individual children of publicationStmt into new class tei.publicationComponents
• new content model defined for change: move date to a required attribute, change item to macro.specialPara, change

respStmt to required who, which points to a

person or personGrp, [schematron rule ... pending work on prosopography]

• define new class tei.recording with members respStmt | equipment | broadcast | date . Then change content model of

recording to use it: p+ | tei.recording+

• define new macro, macro.rendition which contains macro.paraContent and becomes the sole token in the content of rendition; this makes it easier to modify content of rendition eg to include an XML vocabulary
• try changing sourceDesc to have content tei.paragraph+ | ( tei.bibl | tei.sourceDesc )+
• remove tei.teiHeader and

tei.teiText classes

• replace references to note with references to tei.notes in classes and content models
• setting should reference new tei.temporal class

Specific Decisions in Related Areas

In going through each element in the core, textstructure, and header modules looking for improvements in the class system, we came across quite a few other areas where changes are needed.

• remove p from content of langUsage
• change content of foreign to

macro.phraseSeq instead of macro.paraContent.

• change model of teiCorpus to teiHeader, ( TEI | teiCorpus )+
• remember to fix tagdoc of binaryObject: attributes need proper declarations
• add mimeType attribute to rendition
• consider making encodingDesc and tagsDecl require at least one child element
• remove tei.Incl from monogr, biblFull, and all of teiHeader
• suggested changing name of tei.tpParts to tei.model.titlePageComponents
• default position is to change text to

tei.text wherever it occurs. Only exception noticed so far is

binaryObject but there may be others.

LR investigate merging label and lbl.

SR fix stylesheet so that namespace isn't lost from xml:id and xml:lang in examples

eds. & SR sort out getting g into all references to text; i.e., make new class tei.text with only one member, g, new macro macro.text which is ( text | tei.text)*.

On Naming

We had time to discuss the major structural names, listed below.

datatypes* tei.data.* attribute class* tei.att.* model class* tei.model.* macro* tei.macro.* module* tei..*

We agreed that both the actual name and the corresponding filename should be in camelCase. We did not resolve whether or not the tei. prefix would be included in filenames or not.

Several members (SB, JC, SR, and CW) met at OUCS 2005-09-28 from ~09:30 to 11:57 and continued the naming discussion. The results of this meeting have been incorporated into ED W 87, thanks to SR.

Further Work

We agreed that work was needed in the following areas, but could not be taken up at the current meeting.

• tei.sourceDesc needs a new name
• whether or not the various docXX elements are needed, and if so should they still be in divtop and fmchunk
• Need to manage two things in ND: the murky mess of names, and prosopographic data. Could be a complete WG or a quick hack
• fix the content model of list, possibly dividing into two: list and a separate glossList
• tei.chunk needs to be broken up into subclasses