If the data has been improperly prepared, even the most advanced local system will be affected. For guidance, consult with the local system vendor about the system's data requirements. In selecting a retrospective conversion vendor, libraries should determine if conversion into MARC format is available and if all media formats are supported. Most of the online bibliographic databases use full MARC format and support resource sharing. If these two areas are important to your project, be certain that the vendor you select offers you both.
Libraries can use a number of methods to complete a retrospective conversion project.
In some cases, a combination of methods may be preferable. The choice hinges primarily on the library's budget, collection, quality demands, time constraints, and staff. Below are five retrospective conversion options. In a Full Vendor Contract, your library hires a vendor to do the complete project. Some vendors charge one unit cost for every record processed, including matching to existing records or inputting an original record.