Both home- and office-based employees worked the same shift period, in their same work groups, under the same managers as before, and logged on to the same computer system, with the same equipment, and the same work-order flow. The only difference between the two groups was the location where they worked. Ctrip keeps extensive, computerized records of the times employees are actually working, the sales they make and the quality of their interactions with customers, and this data allowed us to compare the performance of those at home and those in the office.