MEDLARS: PERFORMANCE, PROBLEMS, POSSIBILITIES.

Operational experience during the first year of MEDLARS is described in relation to the Library's primary objectives of index publication, recurring bibliographies, and demand search services. Progress toward the implementation of two secondary objectives-the input of cataloging copy and the decentralization of the system-is also reported. MEDLARS has been intensively tested during its first operational year, its strengths and weaknesses have been identified, and it is now prepared to develop its service potential.