PairedData (version 0.9.9)

BloodLead: Blood lead levels data from Pruzek & Helmreich (2009)

Description

This dataset presents matched paired data corresponding to blood lead levels for 33 children of parents who had worked in a lead related factory and 33 control children from their neighborhood. The two samples have different dispersions and their correlation is small.

Usage

data(BloodLead)

format

A dataframe with 33 rows and 3 columns: rlll{ [,1] Pair factor matched pair of chidren [,2] Exposed numeric blood lead levels (mg/dl) for exposed children [,3] Control numeric blood lead levels for controls }

source

Morton, D., Saah, A., Silberg, S., Owens, W., Roberts, M. & Saah, M. (1982) Lead absorption in children of employees in a lead related industry. American Journal of Epimediology, 115, 549-55.

References

Pruzek, R.M. & Helmreich, J.E. (2009) Enhancing dependent sample analysis with graphics. Journal of Statistics Education, 17 (1).

Examples

data(BloodLead)

# Control values are clealy less dispersed (and inferior)
# than exposed levels
with(BloodLead,plot(paired(Control,Exposed),type="McNeil"))
with(BloodLead,var.test(paired(Control,Exposed)))
with(BloodLead,grambsch.var.test(paired(Control,Exposed)))
with(BloodLead,bonettseier.var.test(paired(Control,Exposed)))

# Correlation is small (bad matching)
with(BloodLead,cor.test(Control,Exposed))
with(BloodLead,winsor.cor.test(Control,Exposed))