Format
A data frame with 24 observations on the following 2 variables.
Group
Treatment: Caffeine
Sleep
Words
Number of words recalled
Source
Mednick, Cai, Kanady, and Drummond, "Comparing the benefits of
caffeine, naps and placebo on verbal, motor and perceptual memory",
Behavioural Brain Research, 193 (2008), 79-86.