cushny | R Documentation |
The classic data set used by Gossett (publishing as Student) for the introduction of the t-test. The design was a within subjects study with hours of sleep in a control condition compared to those in 3 drug conditions. Drug1 was 06mg of L Hscyamine, Drug 2L and Drug2R were .6 mg of Left and Right isomers of Hyoscine. The detal1, delta2L and delta2R are changes from the baseline control.
data(cushny)
A data frame with 10 observations on the following 7 variables.
Control
Hours of sleep in a control condition
drug1
Hours of sleep in Drug condition 1
drug2L
Hours of sleep in Drug condition 2
drug2R
Hours of sleep in Drug condition 3 (an isomer of the drug in condition 2
delta1
Change from control, drug 1
delta2L
Change from control, drug 2L
delta2R
Change from control, drug 2R
The original analysis by Student is used as an example for the t-test function, both as a paired t-test and a two group t-test. The data are also useful for a repeated measures analysis of variance.
Cushny, A.R. and Peebles, A.R. (1905) The action of optical isomers: II hyoscines. The Journal of Physiology 32, 501-510.
Student (1908) The probable error of the mean. Biometrika, 6 (1) , 1-25.
See also the data set sleep and the examples for the t.test
data(cushny) with(cushny, t.test(drug1,drug2L,paired=TRUE)) #within subjects error.bars(cushny[1:4],within=TRUE,ylab="Hours of sleep",xlab="Drug condition",main="95% confidence of within subject effects")