[FinB] Mаlinа wаnts tо imprоve the perfоrmance of the assembly line worker she manages. Currently, the worker produces an average of 500 units per day in baseline. Malina first implements a feedback system where she posts the worker’s daily productivity. Almost immediately after the feedback system’s implementation, productivity increases to an average of 750 units per day. After 2 weeks at this level, Malina implements a pay-for-performance system with bonuses based on productivity rates. This performance system produces an average of 1,000 units per day for the next 2 weeks. Malina continues implementing these interventions in this same order without randomization and sees similar behavior patterns. Later, Malina implements the performance system immediately following the baseline and finds that it is not as effective as it had been during the original testing period. The results of these data are most likely being impacted by which confound?