Numerical techniques, such as finite element methods (FEM), have been widely used in predicting defect signatures in nondestructive evaluation (NDE). The test conditions in the numerical models are deterministic in nature. However, signals generated by identical flaws are usually different under practical testing conditions. This affects the reliability of NDE methods. A considerable amount of attention has been focused towards quantifying the reliability of a variety of NDE methods, which has led to development of models for evaluating probability of detection (POD). Sources of variabilities that influence POD in NDE systems vary due to different testing modalities. POD models not only help in improving accuracy in flaw detection but also help in optimizing operational parameters. The Taguchi method, also called robust design in literature, is a well-established technique for optimizing the design parameters in an experiment.;This dissertation presents a comprehensive POD model for quasi-static electromagnetic NDE. Applications of Taguchi methods as well as POD models in magnetic flux leakage (MFL) and magneto-optic/eddy current imaging inspections are investigated in this research.