From a group of 996 employees, 503 volunteered to participate, of which 249 were qualified by virtue of having worked at the firm for 6 months, having broadband internet, and having their own workspace in their homes. From this group, those with even-numbered birthdays (day of birth ending in 0, 2, 4, etc.) were randomly selected to work at home. Those with odd-numbered birthdays were required to continue working from the office and served as the comparison group. Employees selected to participate in the program worked four days per week from home and one day in the office. They were still supervised by their team leader, who always worked in the office, and they maintained the same hours, wage levels, type of work, and computer and communication equipment.