The computer program AMPS has been used to explore experimental situations for testing the validity of bimolecular and single‐carrier driven models of metastable defect generation in a‐Si:H. In this study, AMPS was used to evaluate the effect of blue laser soaking on the experimentally‐measured quantum efficiency of a‐Si:H Schottky barrier structures. Results of these simulations indicate that neither a surface degradation nor a bulk degradation model alone can satisfactorily explain the experimentally observed degradation in quantum efficiency due to blue laser soaking. These results suggest that neither a bimolecular nor single‐carrier‐driven defect generation mechanism can clearly account for the degradation experimentally observed.