There are 34 relationships defined in LRM. This is not a closed list:
"Any additional relationships needed by a particular implementation can
be defined as sub-types of the additional relationships defined in the
model, or of the top relationship." (p. 45)
However, I am bewildered by what seems to me a discrepancy between very
general and very specific relationships in the list. The selection of
relationships defined seems to me somewhat arbitrary and not really well
balanced. I would prefer to have more relationships on a middle level of
For example, sometimes we find very detailed relationships. Look at
LRM-R26 (Manifestation - has reproduction/is reproduction of -
Manifestation) and LRM-R27 (Manifestation - has alternate/has alternate
- Manifestation). If we compare this to RDA, we find the element
"Related Manifestation" (RDA 27.1) on the highest level. Then there is,
in appendix J.4.2, "equivalent (manifestation)" with several sub-terms,
among them "reproduced as (manifestation)/reproduction of
(manifestation)" and "also issued as". So, the RDA equivalents of
LRM-R26 and R27 are on the third (!) hierarchical level. However, there
is no general relationship defined between two manifestations in LRM
(something like: Manifestation - is associated with/is associated with -
Manifestation". I think this is rather amazing for a model which claims:
"In the FRBR-LRM model, the relationships are declared in a general,
abstract way and thus enable implementers to include additional details
in a consistent and coherent way by introducing additional types." (p. 43).
Another example are the relationships between two agents. Again we find
some rather specific relationships (e.g. Agent - is member of/has member
- Collective Agent), but no general relationship between two agents.
Therefore, if we want to express that person A is married to person B by
using the relationships defined in LRM, we need to fall back on the most
general relationship, FRBR-LRM1 (Res - is associated with/is associated
with - Res), as there is no specific relationship which could be used. I
would much prefer LRM to have, for every entity, a general relationship
between two entities of the same kind, e.g. "Work to Work", "Expression
to Expression", "Agent to Agent" a.s.o.
A second point which struck me when looking through the list of
relationships: Why is there no whole/part relationship for Item?
Whole/part relationships are defined for 7 out of 11 entities. I do
understand that a whole/part relationship doesn't make much sense for
Person, which in turn means that it cannot be defined for the
hiearchically superior entities Agent and Res. But I am at a loss why it
wasn't defined for Item.
Prof. Heidrun Wiesenmueller M.A.
Stuttgart Media University
Nobelstrasse 10, 70569 Stuttgart, Germany