Ameritech's Horizon System

“Horizon” is the integrated library system marketed by Ameritech Library Services. The cataloging and authority control module of this system is a mixture of strengths and weaknesses. The MARC editor is inefficient for use in environments where high productivity is required but will be replaced with a significantly improved editor in the near future. Simultaneous import of MARC records by multiple users is problematic. Bibliographic headings are stored in the form of separate authority records, an approach that offers advantages but also presents significant problems. The flexibility of non-MARC edit forms is a major plus.