Equivalence classes It is inappropriate to test by brute force, using every possible input value -Takes a huge amount of time Is impractical -Is pointless You should divide the possible inputs into groups which you believe will be treated similarly by all algorithms -Such groups are called equivalence classes a tester needs only to run one test per equivalence class The tester has to understand the required input appreciate how the software may have been designed www.oseng.com C Lethbridge/Laganiere 2001 Chapter 10: Testing and Inspecting for High Quality 6© Lethbridge/Laganière 2001 Chapter 10: Testing and Inspecting for High Quality 6 Equivalence classes • It is inappropriate to test by brute force, using every possible input value —Takes a huge amount of time —Is impractical —Is pointless! • You should divide the possible inputs into groups which you believe will be treated similarly by all algorithms. —Such groups are called equivalence classes. —A tester needs only to run one test per equivalence class —The tester has to - understand the required input, - appreciate how the software may have been designed