Promising new education interventions are potentially being 'unnecessarily scrapped' because trials to test their effectiveness are insufficiently faithful to the original research, a study warns. Researchers ran a large-scale computer simulation to examine how much 'fidelity' compromises the results of school-based trials of new learning innovations and strategies. 'Fidelity' is the extent to which these evaluations adhere to the original research on which the educational intervention is based.