Typographical errors in bibliographic records can cause retrieval problems in online catalogs. This study examined one hundred typographical errors in records in the OCLC WorldCat database. The local catalogs of five libraries holding the items described by the bibliographic records with typographical errors were searched to determine whether each library had corrected the errors. The study found that only 35.8 percent of the errors had been corrected. Knowledge of copy cataloging error rates can help underscore the importance of quality data in bibliographic utilities and, further, can serve as an indication to libraries whether they need to pay more attention to correcting typos in the copy cataloging process. [ABSTRACT FROM AUTHOR]