Thispaper presents the results of an experiment that compared error detection capability of voting, instrumentation,and Fagan inspection methods. Several experimentshave measured effectivenessof variouserror detectionmethods.However, most experimentshave used different programs; consequently, the results are generally incompatible and do not allow one to make objective comparison on the cost-effectivenessof various approaches. No software can be developed using unlimited amount of resources, practitioners need empirical and objective data on the cost-effectivenessof various errw detectionmethodsto decide which methods to use during sojbvare development. Results of this experimentissignificant becausethese methods have been applied to the same program. Futhermore,the participant's educational and industrial experience are comparable to that of the previous experiments.. We conprmed the previous Pnding that detecting errorsin reliableprogramsis diBcult; none of the three methods de...