Testing at boundaries of equivalence classes More errors in software occur at the boundaries of equivalence classes The idea of equivalence class testing should be expanded to specifically test values at the extremes of each equivalence class e. g The number 0 often causes problems E. g. If the valid input is a month number(1-12) Test equivalence classes as before Test 0, 1, 12 and 13 as well as very large positive and negative values www.oseng.com C Lethbridge/Laganiere 2001 Chapter 10: Testing and Inspecting for High Quality© Lethbridge/Laganière 2001 Chapter 10: Testing and Inspecting for High Quality 10 Testing at boundaries of equivalence classes • More errors in software occur at the boundaries of equivalence classes • The idea of equivalence class testing should be expanded to specifically test values at the extremes of each equivalence class —E.g. The number 0 often causes problems • E.g.: If the valid input is a month number (1-12) —Test equivalence classes as before —Test 0, 1, 12 and 13 as well as very large positive and negative values