# R: Student's Sleep Data

sleep {datasets} | R Documentation

## Student's Sleep Data

### Description

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

### Usage

    sleep

### Format

A data frame with 20 observations on 2 variables.

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

### 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

    require(stats)
    ## Student's paired t-test
    t.test(extra ~ group, data = sleep, paired = TRUE)

[Package datasets version 2.6.0 Index]