"Things to Know About Subject Identification"

Every community, and every community of practice, has peculiar ways of
talking about the things that are of interest to them.  Over time,
these "universes of discourse" necessarily evolve and diversify.

Information technology providers and their customers typically ignore
these facts when systems are designed and purchased.  Customers
generally can't imagine systems that support constantly-changing
universes of discourse, or multiple universes of discourse.  Vendors
don't offer such systems because customers don't demand them, and
vendors have significant disincentive to offer such innovations.

As a consequence, information management systems can function only
within the single universe of discourse in terms of which they were
originally specified.  For the sake of simplicity, this is a good
thing, because *within* a single universe of discourse, the
distinction between, for example, a citizen and a database record
about a person can be safely ignored.  

However, the overall situation in which decision-makers find
themselves is not so simple.  There is no single universe of
discourse; there are many such universes, many of them are constantly
changing, and the number of such universes only increases.  If a
decision maker can only know things about a given subject that a given
computer system can say about it, then he or she must be conversant
with an unbounded number of different universes of discourse.  That
approach can work for a while, but not forever.

The question of what to do about the fact that different systems and
different communities talk about the same things in different,
changeable ways cannot be solved until we're willing to acknowledge
that this problem actually exists, and that it cannot be solved by
everybody agreeing to use any single way of identifying what they're
talking about.

Examples of diverse ways of identifying subjects will be discussed,
along with approaches whereby different communities can exploit each
other's information resources without compromising their ability to
fulfill their unique missions, or their capacity to adapt
independently to changing requirements and conditions.