In science, a variable is something that can be changed, measured or controlled in an experiment. Scientists look at variables to understand how they affect things. A variable is any one of the things ...

Although quality is often measured by the joint level of several correlated random variables, it is common to find in practice, control decisions based on individual Shewhart charts. Hotelling (1947) ...

We submit our recent systemic democratic peace research to the control variable doctrine of James Lee Ray, as codified in his 2003 treatise. In particular, we seek to determine whether international ...