Last data update: 2014.03.03
R: Reaction Time Data
Reaction Time Data
Description
Data from Maxwell and Delaney (1990, p. 497) representing the reaction times of 10 subjects
in some task where visual stimuli are tilted at 0, 4, and 8 degrees; with noise absent or present.
Each subject responded to 3 tilt x 2 noise = 6 conditions. The data thus comprise a
repeated measure design with two within-S factors.
Usage
data(ReactTime)
Format
A data frame with 10 observations giving the reaction time for the 6 conditions.
deg0NA
a numeric vector
deg4NA
a numeric vector
deg8NA
a numeric vector
deg0NP
a numeric vector
deg4NP
a numeric vector
deg8NP
a numeric vector
Source
Baron, J. and Li, Y. (2003).
Notes on the use of R for psychology experiments and questionnaires ,
http://cran.r-project.org/doc/contrib/Baron-rpsych.pdf
References
Michael Friendly (2010). HE Plots for Repeated Measures Designs. Journal of Statistical Software ,
37(4), 1-40. URL http://www.jstatsoft.org/v37/i04/ .
Maxwell, S. E. & Delaney, H. D. (1990).
Designing Experiments and Analyzing Data: A model comparison perspective .
Pacific Grove, CA: Brooks/Cole.
Examples
data(ReactTime)
(RT.mod <- lm(as.matrix(ReactTime)~1))
# within-S factors
within <- expand.grid(tilt=ordered(c(0,4,8)), noise=c("NA", "NP"))
Anova(RT.mod, idata=within, idesign=~tilt * noise)
heplot(RT.mod, idata=within, idesign=~tilt * noise, iterm="tilt")
# plotting means and std errors directly
levels <- expand.grid(Tilt=c(0,4,8), noise=c("NA", "NP"))
(means.df <- data.frame(levels, mean=colMeans(ReactTime), se=sqrt(diag(var(ReactTime)))/9))
with(means.df, {
plot(Tilt, mean, type="n", main="Reaction Time data", xlab="Tilt", ylab="Reaction time")
colors <- rep(c("red", "blue"), each=3)
pts <- rep(c(15, 16), each=3)
lines(Tilt[1:3], mean[1:3], col="red", lwd=2)
lines(Tilt[4:6], mean[4:6], col="blue", lwd=2)
points(Tilt, mean, pch=pts, col=colors, cex=1.2)
arrows(Tilt, mean-se, Tilt, mean+se, angle=90, code=3,
col=colors, len=.05, lwd=2)
# labels at last point, in lieu of legend
text(Tilt[3], mean[3]-10, labels="NA", col="red", pos=1)
text(Tilt[6], mean[6]-10, labels="NP", col="blue", pos=1)
}
)
Results