1. Preventive controls deter problems before they arise. Examples include hiring qualified personnel, segregating employee duties, and controlling physical access to assets and information. 2. Detective controls discover problems that are not prevented. Examples include duplicate checking of calculations and preparing bank reconciliations and monthly trial balances. 3. Corrective controls identify and correct problems as well as correct and recover from the resulting errors. Examples include maintaining backup copies of files, correcting data entry errors, and resubmitting transactions for subsequent processing. Internal controls are often segregated into two categories:
