Steve Black wondered how other serials systems handled
"skipped issues and mysterious pattern changes".  The
Library of Congress' Serials Management System (SMS) is
based on the following principles:

1)  Patterns change, often with no advance notice.

2)  Workflow demands that items that don't "fit" be
checked in anyway.  Items cannot be held while a new
pattern is determined.

3)  Accessioners, confronted with the printed item,
know better than the system how an issue describes itself.

3)  Error is not always obvious.  Sometimes it's not
even error.

SMS is a value-based projective system. Usually when
you check in an item, each enumeration and chronology
value is captured and stored seperately.  There is
some validation, in the sense that a classic monthly
(monthly, 12 no. per v.) will have 4 boxes, and all
4 must be filled in.  But if you need to check in an
item for v. 8 no. 13 Jan. 1997, you may do so.  If
you want to check in an item for  v. 8 no. 12 pt. 1
Jan. 1997, (5 boxes), you will need to either check
it in as a "freeform issue", i.e. as a string blob,
or change the title's pattern to one with the
appropriate 5 boxes.

While checkin is only partly influenced by the pattern,
the gap reporting is completely driven by the pattern.
Even here, though, there's "wiggle room".  Most series
of issues are evaluated first by their enumerations.
If these conform with the pattern, then chronologic
discrepancies are disregarded.  In some cases, if
an enumeration is bad but the chronologies are OK, it
won't cause a gap.

A good serials system has to be tolerant (offering
options), well educated (knowledgeable about pattern
details), and kind (forgiving of error).

      -------------------------------------
      Claudia McNellis
         Information Technology Services
         Library of Congress
         Washington, DC 20540-9334
      cmcn@loc.gov
      (202)707-9606
      -------------------------------------