If Productivity Increased in a Factory After All of Its

Multiple Choice

If productivity increased in a factory after all of its employees were switched to a work schedule consisting of four 10-hour days, should management really credit the schedule switch with the improvement?

A) Yes
B) Yes, but only if no workers had left the factory
C) No. There are too many threats to validity to draw that conclusion
D) No. You would need to conduct a survey to be sure.