Operating procedures for keyboard data entry in avionics are analyzed. The type of information being entered may be identified either before or after entry of the alphanumeric characters. The keys which are used to identify the type of data may be collected in a centralized control unit or distributed throughout the cockpit adjacent to the associated displays. The Collins NCS-31 and the King KCU 565 navigation and control systems are discussed as illustrations of two sets of choices for operating procedures. Emphasis is placed upon correspondence between the thought processes associated with data entry and the pilot's actions in entering data.