 All data will be entered by the double entry method. Referential data rules, valid values, range checks, and consistency checks against data already stored in the database will be supported. Checks will be applied at the time of data entry into a specific field. Additional errors will be detected by programs designed to detect missing data or specific errors in the data. The investigator who receives the inquiry will respond by checking the original forms for inconsistency, checking other sources to determine the correction, modifying the original paper form entering a response to the query. 