Dataset: caffeine_mixed.dat Source: H.P.A. Van Dongen, E. Olofson, D.F. Dinges, G. Maislin (2004). "Mixed Model Regression Analysis and Dealing with Interindividual Differences," Methods in Enzymology, pp. 139-171. Description: Results of experiment on effects of low-dose caffeine vs placebo on number of psychomotor vigilance performance laps, measured on 4 days of total sleep deprivation, with 13 subjects per group. Variables/Columns Subject id 7-8 Trt 16 /* 1=Caffeine, 2=Placebo */ Day0 response 19-24 Day1 response 27-32 Day2 response 35-40 Day3 response 43-48