PrisonStress {PairedData} | R Documentation |
Stress in prison
Description
This dataset gives the PSS (stress measurement) for 26 people in prison at the entry and at the exit. Part of these people were physically trained during their imprisonment.
Usage
data(PrisonStress)
Format
A dataframe with 26 rows and 4 columns.
[,1] | Subject | factor | anonymous subjects |
[,2] | Group | factor | sport or control |
[,3] | PSSbefore | numeric | stress measurement before training |
[,4] | PSSafter | numeric | stress measurement after training |
Source
Private communication. Charlotte Verdot, CRIS, Lyon 1 University, FRANCE
References
Verdot, C., Champely, S., Massarelli, R. and Clement, M. (2008) Physical activities in prison as a tool to ameliorate detainees mood and well-being. International Review on Sport and Violence, 2.
Examples
data(PrisonStress)
# The two groups are not randomized!
# The control group is less stressed before the experiment
with(PrisonStress,boxplot(PSSbefore~Group,ylab="Stress at the eginning of the study"))
# But more stressed at the end!
with(PrisonStress,boxplot(PSSafter~Group,ylab="22 weeks later"))
# So the effects of physical training seems promising
with(PrisonStress,plot(paired(PSSbefore,PSSafter),groups=Group,type="BA",facet=FALSE))
# Testing using gain scores analysis
difference<-PrisonStress$PSSafter-PrisonStress$PSSbefore
t.test(difference~PrisonStress$Group,var.equal=TRUE)
# Testing using ANCOVA
lmJail<-lm(PSSafter~PSSbefore*Group,data=PrisonStress)
anova(lmJail)
# Testing using repeated measures ANOVA
PSS<-c(PrisonStress$PSSbefore,PrisonStress$PSSafter)
Time<-factor(rep(c("Before","After"),c(26,26)))
Subject<-rep(PrisonStress$Subject,2)
Condition<-rep(PrisonStress$Group,2)
aovJail<-aov(PSS~Condition*Time+Error(Subject))
summary(aovJail)
[Package PairedData version 1.1.1 Index]