An experimental evaluation of inspection and testing for detection of design faults

The two most common strategies for verification and validation, inspection and testing, are in a controlled experiment evaluated in terms of their fault detection capabilities. These two techniques are in the previous work compared applied to code. In order to compare the efficiency and effectiveness of these techniques on a higher abstraction level than code, this experiment investigates inspection of design documents and testing of the corresponding program, to detect faults originating from the design document. Usage-based reading (UBR) and usage-based testing (UBT) were chosen for inspections and testing, respectively. These techniques provide similar aid to the reviewers as to the testers. The purpose of both fault detection techniques is to focus the inspection and testing from a user's viewpoint. The experiment was conducted with 51 Master's students in a two-factor blocked design; each student applied each technique once, each application on different versions of the same program. The two versions contained different sets of faults, including 13 and 14 faults, respectively. The general results from this study show that when the two groups of subjects are combined, the efficiency and effectiveness are significantly higher for usage-based reading and that testing tends to require more learning. Rework is not taken into account, thus the experiment indicates strong support for design inspection over testing.