|This article does not cite any references or sources. (December 2009)|
For example, if an input field is meant to accept only integer values 0–100, entering the values -1, 0, 100, and 101 would represent the boundary cases. A common technique for testing boundary cases is with three tests: one on the boundary and one on either side of it. So for the previous example that would be -1, 0, 1, 99, 100, and 101.