2 Systematic Selective Distinct Nonsystematic Identical

| Software requirements speciications (SRS) are often validated manually. One such process is inspection, in which several reviewers independently analyze all or part of the speciication and search for faults. These faults are then collected at a meeting of the reviewers and author(s). Usually, reviewers use Ad Hoc or Checklist methods to uncover faults. These methods force all reviewers to rely on nonsystematic techniques to search for a wide variety of faults. We hypothesize that a Scenario-based method, in which each reviewer uses diierent, systematic techniques to search for diierent, speciic classes of faults, will have a signiicantly higher success rate. We evaluated this hypothesis using a 3 2 4 partial facto-rial, randomized experimental design. Forty eight graduate students in computer science participated in the experiment. They were assembled into sixteen, three-person teams. Each team inspected two SRS using some combination of Ad Hoc, Checklist or Scenario methods. For each inspection we performed four measurements: (1) individual fault detection rate, (2) team fault detection rate, (3) percentage of faults rst identiied at the collection meeting (meeting gain rate), and (4) percentage of faults rst identiied by an individual, but never reported at the collection meeting (meeting loss rate). The experimental results are that (1) the Scenario method had a higher fault detection rate than either Ad Hoc or Checklist methods, (2) Scenario reviewers were more eeec-tive at detecting the faults their scenarios are designed to uncover, and were no less eeective at detecting other faults than both Ad Hoc or Checklist reviewers, (3) Checklist reviewers were no more eeective than Ad Hoc reviewers, and (4) Collection meetings produced no net improvement in the fault detection rate { meeting gains were ooset by meeting losses.