Many Americans complain about being sleep deprived. A team of psychologists researched the reasons for this sleep deprivation. After determining that one reason was poor time management, they devised a program to help people manage their time better. They recruited a random sample of 30 people at a major shopping center and randomly split them into three groups of size 10. Group 1: the controls, received a logbook asking them to record the number of hours slept for a week, but nothing else. Group 2: the informed group, was shown a video to help improve time management. Group 3: the intervention, participated in a twoday training course on improving time management. Groups 2 and 3 were also asked to keep records for one week on the number of hours slept. The psychologists were interested in learning if providing information or an intervention affects sleep time.