Verification and validation of a diffraction program

In the context of electromagnetics programs, verification is the checking of input data and validation is the checking of output results. These divide into several sections which partially correspond to the IEEE/ANSI definitions as follows (IEEE/ANSI terms in brackets): checking data entry for correct type and range (not allowed for in IEEE/ANSI); checking the program specification (error); checking the documentation (defect); checking for bugs (fault); and checking the algorithms (error). The author considers these and points out some of the problems which arise in attempting to verify or validate an electromagnetic program