The complexity of instructional design may produce cognitive overload, high stress level and anxiety. This may increase fatigue, facilitate errors, and is associated with inferior task performance which may impede memorization of learned skills resulting in inefficient learning/simulation failure. Subjectively reported scales can accurately identify the level of perceived workload and mental demand in individuals during simulation tasks. One example is the National Aeronautics and Space Administration (NASA)-TLX - the most accepted subjective measure of human workload in various industries including medicine.