An experiment was performed to investigate the effect of sleep on attention performance. People were matched on all relevant characteristics and then randomly assigned to a group. Participants assigned to Group 1 slept for 8 hours every night. People in Group 2 slept for 5 hours every night. After following this sleeping pattern for two weeks, all participants completed a computer attention task. Person Group Age Hours Prefer ATT Score 1 1 22 5 M 80 2 1 33 3 N 52 3 1 28 3 N 85 4 1 29 8 A 65 5 1 19 9 A 92 6 1 22 4 A 87 7 1 32 7 N 72 8 1 31 5 M 71 9 1 28 8 N 78 10 1 19 4 N 80 11 2 34 6 M 40 12 2 21 7 N 45 13 2 29 9 A 36 14 2 26 3 A 25 15 2 18 4 A 36 16 2 29 8 N 46 17 2 35 2 N 60 18 2 22 6 N 33 19 2 28 8 M 40 20 2 29 6 A 44 Explanation of Variables: Group - Group 1 slept for 8