As a follow-up to our meeting in Washington I have gone back to the
entity-relationship model that was developed to reflect the Anglo-American
Cataloguing Rules, and have tried looking at it from an events-focussed
perspective.

The attached synoptic table is designed to "display" the AACR model in a
structure that lends itself more directly to comparison with the events
structure that is set out in the INDECS model, and may help to illustrate
more clearly where the two models converge or overlap.  (The table was
created in Excel 5.0.  If you have difficulty opening or printing it, let me
know and I will see if Carl can post a PDF version on the ABC web site.)

The table provides a synopsis of the AACR model in a matrix structure.
Along the veritcal axis (in the left-hand column of the table) I have listed
and categorized the events that are either explicit or implicit in the AACR
model.  Across the horizontal axis (in the headings at the top of the table)
I have grouped the other key "real world" elements in the AACR model
according to the basic role types identified in the INDECS model (agent,
patient, input, output, context).  The elements listed on the horizontal
axis are organized hierarchically to reflect classes that in the AACR model
are in most cases defined as entity types and their respective subtypes.
(Further explanation of the elements identified in the table is appended
below.)

Reading across the table, for each event listed in the left-hand column, the
letters A, P, I, O, and C indicate which of the elements on the horizontal
axis may be cast in the role of agent, patient, input, output, or context,
respectively.  The designations A, P, I, O, and C in effect define for the
AACR model the domain constraint (to use RDF terminology) for each of the
relations listed in the event column.  The table as a whole thus serves as a
short-hand means of displaying the INDECS-styled event structures embedded
in the AACR model.  In effect, the table functions as a specification for
the "lens" through which the cataloguer using AACR views the events
associated with the objects being described in the catalogue record.  

I think it would be useful to compile a parallel table reflecting the INDECS
model, so that we could then "overlay" one on the other to see where they
overlap, converge, or collide.  If Godfrey and Mark could prepare the INDECS
table for comparison, I think we might find that we have a tool we could use
to start building the ABC model.  If we could overlay an INDECS table on the
AACR table, and reconcile the two, we might have a sufficient base to
facilitate the development of additional overlays for the other metadata
domains represented in the group.

Tom

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Explanation of elements in the AACR synoptic table

The following notes are intended simply to clarify the derivation of the
elements listed in the table, by mapping those elements to their
counterparts in the AACR model.  Definitions for the source elements can be
found in the documentation on the AACR model: (Part I)
http://www.nlc-bnc.ca/jsc/aacrdel.htm; (Part II)
http://www.nlc-bnc.ca/jsc/aacrdel2.htm. 

Event

Several of the event classes (viz., creating, modifying, editing, compiling,
performing, issuing, producing, manufacturing, releasing) correspond
directly to events that are represented as associative entities in the AACR
model.  For purposes of comparison with the INDECS model, the names
identifying the associative entities in the AACR model (viz., creation,
modification, editing/compiling, performance, emanation, production,
manufacture, release) have been systematically recast in the form of
gerunds.

The sub-classes listed under creating (viz., writing, composing, making art)
represent three types of creating events around which the rules in AACR are
structured.  The distinctions represented by those specific sub-classes
reflect distinctions between writers, composers, and artists that must be
made by the cataloguer when determining the choice of entry for new works of
"mixed responsibility."  The sub-classes listed under modifying (viz.,
abridging, summarizing, revising, translating, arranging, transcribing
adding part/accompaniment, adapting) represent types of modifying events
around which the rules in AACR are structured, and again reflect
distinctions that the cataloguer must make when determining the choice of
entry for "works that are modifications of other works." 

Another event class (adopting) has been introduced to reflect a subset of
the associations delineated in Part II of the AACR model through the "other
association" entity.

Two additional event classes (viz., reproducing, reformatting) reflect
events that are implicit in the item-to-item relationships delineated in
Part I of the AACR model (viz., reproduction, other format).  A third event
class in the same group (reconfiguration) has no direct counterpart in the
AACR model but was derived from an item-to-item relationship type in the
IFLA model.

Another two event classes (complementing, extending) reflect events that are
implicit in two groups of work-to-work relationships delineated in Part II
of the AACR model (viz., illustration, musical setting, cadenza,
libretto/text, choreography, index--all of which are subsumed under
complementing--supplement, continuation/sequel--which are subsumed under
extending).  For the purposes of this table, they have been added to the
list of event classes as a means of representing the association between two
concept entities (i.e., two works) through an event relationship. 

The last event class in the list (transferring) was derived from the
"transfers" relationship in Part I of the AACR model that links persons and
corporate bodies to the entity "ownership".

Agent

The two classes listed under the agent role (person, corporate body)
correspond directly to the entities so named in the AACR model.

Patient / Input / Output

The first class listed under the patient/input/output role (item)
corresponds directly to the entity so named in the AACR model.  In the
model, as in the rules themelves, item functions simply as a "cypher"
entity, a short-hand means of referring to the object on which the catalogue
description is focussed.  The "real world" entities that are tagged as item
are normally either a collection, a document, or a copy (each of which is
defined as an entity in its own right in the AACR model).  For the purposes
of displaying the model in this table, collection, document, and copy have
been treated as sub-classes of item.

The second class listed under the patient/input/output role (content)
corresponds directly to the entity so named in the AACR model.  In Part II
of the model, the entity defined as content is directly associated with the
entity defined as work (the relationship is expressed in the form content -
[is] manifestation of - work).  For the purposes of displaying the model in
this table, the patient/input/output role is associated simply with the
entity defined as content without reflecting the higher level of abstraction
that is represented by the entity defined as work.

The sub-classes listed under content, with one exception, correspond
directly to the entity sub-types defined for the content entity in the AACR
model (literary content, musical content, graphic content, cartographic
content, cinemagraphic content, data content, computer program content).
The one exception (choreographic) reflects a sub-class of content that is
implicit in one of the work-to-work relationships (choreography) defined in
Part II of the model.

The third class listed under the patient/input/output role (infixion)
corresponds directly to the entity so named in the AACR model.  The
sub-classes listed under infixion represent a re-working of the entity
sub-types defined for the infixion entity in the AACR model (sound
recording, film, videorecording, computer file, graphic content, microform,
alternative format materials).  For the purposes of displaying the model in
this table, a first-order sub-classification of infixion, using mode of
expression as the basis for the sub-classification, was considered to be
more useful than the sub-classification reflected in the model.  The
re-working is nevertheless consistent with the attributes of infixion that
are captured by AACR.

The fourth class listed under the patient/input/output role (physical
carrier) corresponds directly to the entity so named in the AACR model.  The
sub-classes listed under physical carrier represent an expansion from the
one entity sub-type (printed book) defined for the physical carrier entity
in the AACR model.  For the purposes of displaying the model in this table,
physical carrier has been "deconstructed" and two first-order
subclassifications have been juxtaposed.  The first set of sub-classes
(sheet/card, disc, tape, film, model) represent the storage media per se,
while the second set (book, cartridge, cassette, reel, roll, mounting)
represent the structure or housing for the storage medium.  This
"deconstructed" sub-classification was considered to be more useful than the
fragmentary sub-classification reflected in the model, but is nevertheless
consistent with the attributes of physical carrier that are captured by
AACR.

Context

The two classes listed under the context role (time, place) are not
reflected as entities per se in the AACR model.  However, the sub-classes of
time (period, year, date) and place (country, state/province, local place,
institution) occur repeatedly in the model as attributes associated with
various events (e.g., date of creation, date of signing of a treaty or
protocol, date/place of production, date/place of manufacture, date/place of
release, date of transfer of ownership).  For purposes of displaying the
model in this table, those attributes have been highlighted as sub-classes
of the two notional classes time and place, in order to facilitate the
identification of the associations between specific events and time and
place that are captured in the cataloguing rules.