Where data must be entered manually, ensure that it is selected from preset options (e. . , drop-down menus of selections pulled from the database), if possible. c. Use trained operators when possible (help systems and good prompts/examples can assist end users in proper data entry).
d. Follow good user interface design principles that create consistent screen layouts, easy to follow navigation paths, clear data entry masks and formats (which can be defined in DDL), minimal use of obscure codes can be looked up and displayed from the database, not in the application programs), etc. . Immediately check entered data for quality against data in the database, so use triggers and user-defined procedures liberally to make sure that only high-quality data enter the database; wen questionable data are entered (e. g. , “T for gender), immediate and understandable feedback should be given to the operator, questioning the validity of the data.