An example of an interrupted time-series design with nonequivalent groups involves evaluating the impact of reducing a factory's work shifts from $10$ to $8$ hours. Researchers might track the weekly productivity of the factory making the change (the treatment group) for a year before and after the reduction. To improve the study's validity, they could also track the productivity of a similar factory that maintains its original schedule (the nonequivalent control group). If the treatment factory shows a rapid and sustained increase in productivity following the shift change while the control factory's productivity remains stable, it provides compelling evidence that the shortened shifts caused the improvement.