The purpose of this posting is to bring to your attention a new feature
of BOPAC2 the University of Bradford Department of Computing
experimental OPAC. Using Z39.50 technology BOPAC2 provides access to
the catalogues of thirty British academic libraries, four Irish ones,
the Library of Congress and MELVYL. Using a java applet it is able to
provide a variety of innovative methods of OPAC display and to move
from one display to another in a few seconds. Retrievals can be much
larger than those achieved by traditional OPACs. Retrievals of five or
six hundred are possible but may take several minutes to download from
the server library.
The new feature which has recently been added is a select 'subject '
option which is we believe an important development in OPAC display. It
will enable the user to make more effective use of the subject
cataloguing contained in the bibliographic record and it opens up a
new approach to subject retrieval and research The option is available
for immediate use to anyone with access to the Internet and will be
particularly useful to the libraries included in the BOPAC clump.
After a retrieval from one or more of the server libraries the user is
already offered a number of display options. The new development is
based on the 650 tag of the MARC format and produces a list in
alphabetical order of the subject headings provided by this tag within
the retrieval. From this list the user obtains a map of the subject
holdings covered by the retrieval. Users can then select the headings
which are of interest and can move from a short display to a full
display of these records in seconds. In addition a display of the full
MARC record can be obtained by pressing the F2 button. Within this
display another useful feature is available; the FIND facility which
can be used to locate and highlight a tag number or a word from the
Marc records of the retrieval. This new feature can be used to refine a
broad subject retrieval very quickly and it also enables the catalogue
user to assess the effectiveness of the subject indexing and to see how
well the authority control is working
Two good examples of how to use this facility are;
(1) Selecting Hull from the list of servers and searching by author
equals Mozart produces a retrieval of 440. No known OPAC is able to
operate with a retrieval of this size. Starting with the 'select'
subject option produces a list in alphabetical order of the Tag 650
headings that have been used. This in itself gives a picture of the
make up of the works by and about Mozart held by the library. There are
28 different headings used. Each one these or a combination of any of
them can be selected and then displayed.
(2) Selecting Library of Congress from the list of servers and
searching by subject contains 'crab.' produces a retrieval of 92. Using
the select 'subject' facility produces a list of 76 different headings
from which the user is able to select those of interest.
In both cases the initial list of subject headings can be shortened by
selection and then the new selection can itself be broken down using
the select 'subject' option. With this approach the user is able to
refine the original search very quickly. Something which is either not
available or only possible in a limited way for the experienced user..
BOPAC2 can be accessed at
http://www.bopac2.comp.brad.ac.uk/~bopac2/htdocs/evaluate.shtml
----------------------
@bradford.ac.uk
----------------------
@bradford.ac.uk
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|