The percentage of conditions within decision expressions that have been evaluated to both true and false. Note that 100% condition coverage does not guarantee 100% decision coverage. For example, “if (A || B) {do something} else {do something else}” is tested with [0 1], [1 0], then A and B will both have been evaluated to 0 and 1, but the else branch will not be taken because neither test leaves both A and B false.
Source(s):
NISTIR 7878