sleep: Student's Sleep Data

Description Usage Format Details Source References Examples

Description

Data which show the effect of two soporific drugs (increase in hours of sleep compared to control) on 10 patients.

Usage

1

Format

A data frame with 20 observations on 3 variables.

[, 1] extra numeric increase in hours of sleep
[, 2] group factor drug given
[, 3] ID factor patient ID

Details

The group variable name may be misleading about the data: They represent measurements on 10 persons, not in groups.

Source

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, 20.

References

Scheffé, Henry (1959) The Analysis of Variance. New York, NY: Wiley.

Examples

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require(stats)
## Student's paired t-test
with(sleep,
     t.test(extra[group == 1],
            extra[group == 2], paired = TRUE))

## The sleep *prolongations*
sleep1 <- with(sleep, extra[group == 2] - extra[group == 1])
summary(sleep1)
stripchart(sleep1, method = "stack", xlab = "hours",
           main = "Sleep prolongation (n = 10)")
boxplot(sleep1, horizontal = TRUE, add = TRUE,
        at = .6, pars = list(boxwex = 0.5, staplewex = 0.25))