R: Blink data from Preece (1982, Table 2)

Blink

R Documentation

Blink data from Preece (1982, Table 2)

Description

This dataset presents paired data corresponding to average blink-rate per minute of 12 subjects in an experiment of a visual motor task. They had to steer a pencil along a moving track. Each subject was tested under two conditions : a straight track and an oscillating one. Note that the values from subjects 1 and 2 are somewhat different.

Usage

data(Blink)

Format

A dataframe with 12 rows and 3 columns:

[,1]	Subject	factor
[,2]	Straight	numeric	blink rate in first condition
[,3]	Oscillating	numeric	blink rate in second condition

Source

Wetherhill, G.B. (1972) Elementary Statistical Methods, 2nd ed Chapman and Hall: London.

References

Preece D.A. (1982) t is for trouble (and textbooks): a critique of some examples of the paired-samples t-test. The Statistician, 31 (2), 169-195.

Examples

data(Blink)

# Visualizing two "outliers"
with(Blink,plot(paired(Straight,Oscillating),type="profile"))

# Interestingly, the differences for the two outliers are quite "normal"
# so their influence on the t test is negligible
with(Blink,qqnorm(Straight-Oscillating))
with(Blink,qqline(Straight-Oscillating))