Many software testing and automated debugging tools rely on structural coverage techniques. Such tools implicitly assume a relation between individual control-flow choices made in conditional statements during a program run and the outcome of the run. In this paper, we develop the notion of elided choices that, viewed in isolation, have no impact on the outcome of the program. We call the conditionals that make such choices elided conditionals. We develop an experimental framework for discovering elided conditionals. From looking at three programs of varying complexity under this framework, we discovered that elided conditionals do occur, sometimes with alarming frequency. We discuss the impact of elided conditionals on various forms of dynamic analysis and suggest future work that would extend elision to general expressions. Categories and Subject Descriptors D.2.5 [Software Engineering]: Testing and Debugging General Terms Reliability,Experimentation,Verification Keywords Elision,...